Journal articles: 'DSBF'

1

Um, Si-Hyeon, Jin-Sik Kim, Kangseok Lee, and Nam-Chul Ha. "Structure of a DsbF homologue fromCorynebacterium diphtheriae." Acta Crystallographica Section F Structural Biology Communications 70, no. 9 (August 29, 2014): 1167–72. http://dx.doi.org/10.1107/s2053230x14016355.

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Disulfide-bond formation, mediated by the Dsb family of proteins, is important in the correct folding of secreted or extracellular proteins in bacteria. In Gram-negative bacteria, disulfide bonds are introduced into the folding proteins in the periplasm by DsbA. DsbE fromEscherichia colihas been implicated in the reduction of disulfide bonds in the maturation of cytochromec. The Gram-positive bacteriumMycobacterium tuberculosisencodes DsbE and its homologue DsbF, the structures of which have been determined. However, the two mycobacterial proteins are able to oxidatively fold a proteinin vitro, unlike DsbE fromE. coli. In this study, the crystal structure of a DsbE or DsbF homologue protein fromCorynebacterium diphtheriaehas been determined, which revealed a thioredoxin-like domain with a typical CXXC active site. Structural comparison withM. tuberculosisDsbF would help in understanding the function of theC. diphtheriaeprotein.

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Lin, Dongxia, Byoungkwan Kim, and James M. Slauch. "DsbL and DsbI contribute to periplasmic disulfide bond formation in Salmonella enterica serovar Typhimurium." Microbiology 155, no. 12 (December 1, 2009): 4014–24. http://dx.doi.org/10.1099/mic.0.032904-0.

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Disulfide bond formation in periplasmic proteins is catalysed by the DsbA/DsbB system in most Gram-negative bacteria. Salmonella enterica serovar Typhimurium also encodes a paralogous pair of proteins to DsbA and DsbB, DsbL and DsbI, respectively, downstream of a periplasmic arylsulfate sulfotransferase (ASST). We show that DsbL and DsbI function as a redox pair contributing to periplasmic disulfide bond formation and, as such, affect transcription of the Salmonella pathogenicity island 1 (SPI1) type three secretion system genes and activation of the RcsCDB system, as well as ASST activity. In contrast to DsbA/DsbB, however, the DsbL/DsbI system cannot catalyse the disulfide bond formation required for flagellar assembly. Phylogenic analysis suggests that the assT dsbL dsbI genes are ancestral in the Enterobacteriaceae, but have been lost in many lineages. Deletion of assT confers no virulence defect during acute Salmonella infection of mice.

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Walden, Patricia M., Andrew E. Whitten, Lakshmanane Premkumar, Maria A. Halili, Begoña Heras, Gordon J. King, and Jennifer L. Martin. "The atypical thiol–disulfide exchange protein α-DsbA2 from Wolbachia pipientis is a homotrimeric disulfide isomerase." Acta Crystallographica Section D Structural Biology 75, no. 3 (February 26, 2019): 283–95. http://dx.doi.org/10.1107/s2059798318018442.

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Disulfide-bond-forming (DSB) oxidative folding enzymes are master regulators of virulence that are localized to the periplasm of many Gram-negative bacteria. The archetypal DSB machinery from Escherichia coli K-12 consists of a dithiol-oxidizing redox-relay pair (DsbA/B), a disulfide-isomerizing redox-relay pair (DsbC/D) and the specialist reducing enzymes DsbE and DsbG that also interact with DsbD. By contrast, the Gram-negative bacterium Wolbachia pipientis encodes just three DSB enzymes. Two of these, α-DsbA1 and α-DsbB, form a redox-relay pair analogous to DsbA/B from E. coli. The third enzyme, α-DsbA2, incorporates a DsbA-like sequence but does not interact with α-DsbB. In comparison to other DsbA enzymes, α-DsbA2 has ∼50 extra N-terminal residues (excluding the signal peptide). The crystal structure of α-DsbA2ΔN, an N-terminally truncated form in which these ∼50 residues are removed, confirms the DsbA-like nature of this domain. However, α-DsbA2 does not have DsbA-like activity: it is structurally and functionally different as a consequence of its N-terminal residues. Firstly, α-DsbA2 is a powerful disulfide isomerase and a poor dithiol oxidase: i.e. its role is to shuffle rather than to introduce disulfide bonds. Moreover, small-angle X-ray scattering (SAXS) of α-DsbA2 reveals a homotrimeric arrangement that differs from those of the other characterized bacterial disulfide isomerases DsbC from Escherichia coli (homodimeric) and ScsC from Proteus mirabilis (PmScsC; homotrimeric with a shape-shifter peptide). α-DsbA2 lacks the shape-shifter motif and SAXS data suggest that it is less flexible than PmScsC. These results allow conclusions to be drawn about the factors that are required for functionally equivalent disulfide isomerase enzymatic activity across structurally diverse protein architectures.

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Kang, Yun Qing, Guang Fu Yin, Ke Feng Wang, Lin Luo, Li Liao, and Ya Dong Yao. "A Study of Bone-Like Apatite Formation on β-TCP/PLLA Scaffold in Static and Dynamic Simulated Body Fluid." Key Engineering Materials 330-332 (February 2007): 483–86. http://dx.doi.org/10.4028/www.scientific.net/kem.330-332.483.

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The ability of apatite to form on the surface of biomaterials in simulated body fluid (SBF) has been widely used to predict the bone-bonding ability of bioceramic and bioceramic/polymer composites in vivo. Porous β-tricalcium phosphate/poly(L-lactic acid) (β-TCP/PLLA) composite scaffold was synthesized by new method. The ability of inducing calcium phosphate (Ca-P) formation was compared in static simulated body fluid(sSBF) and dynamic simulated body fluid (dSBF). The Ca-P morphology and crystal structures were identified using SEM, X-ray diffraction and Fourier transform infrared (FT-IR) spectroscopy. The results showed that the typical features of bone-like apatite formation on the surface and the inner pore wall of β-TCP/PLLA. Ca-P formation on scaffold surfaces in dSBF occurred slower than in sSBF and was more difficult with increasing flow rate of dSBF. The ability of apatite to form on β-TCP/PLLA was enhanced by effect of each other that has different degradable mechanism. Porous β-TCP/PLLA composite scaffold indicates good ability of Ca-P formation in vitro.

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5

Stenson, Trevor H., and Alison A. Weiss. "DsbA and DsbC Are Required for Secretion of Pertussis Toxin by Bordetella pertussis." Infection and Immunity 70, no. 5 (May 2002): 2297–303. http://dx.doi.org/10.1128/iai.70.5.2297-2303.2002.

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ABSTRACT The Dsb family of enzymes catalyzes disulfide bond formation in the gram-negative periplasm, which is required for folding and assembly of many secreted proteins. Pertussis toxin is arguably the most complex toxin known: it is assembled from six subunits encoded by five genes (for subunits S1 to S5), with 11 intramolecular disulfide bonds. To examine the role of the Dsb enzymes in assembly and secretion of pertussis toxin, we identified and mutated the Bordetella pertussis dsbA, dsbB, and dsbC homologues. Mutations in dsbA or dsbB resulted in decreased levels of S1 (the A subunit) and S2 (a B-subunit protein), demonstrating that DsbA and DsbB are required for toxin assembly. Mutations in dsbC did not impair assembly of periplasmic toxin but resulted in decreased toxin secretion, suggesting a defect in the formation of the Ptl secretion complex.

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Kurokawa, Yoichi, Hideki Yanagi, and Takashi Yura. "Overexpression of Protein Disulfide Isomerase DsbC Stabilizes Multiple-Disulfide-Bonded Recombinant Protein Produced and Transported to the Periplasm in Escherichia coli." Applied and Environmental Microbiology 66, no. 9 (September 1, 2000): 3960–65. http://dx.doi.org/10.1128/aem.66.9.3960-3965.2000.

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ABSTRACT Dsb proteins (DsbA, DsbB, DsbC, and DsbD) catalyze formation and isomerization of protein disulfide bonds in the periplasm ofEscherichia coli. By using a set of Dsb coexpression plasmids constructed recently, we analyzed the effects of Dsb overexpression on production of horseradish peroxidase (HRP) isozyme C that contains complex disulfide bonds and tends to aggregate when produced in E. coli. When transported to the periplasm, HRP was unstable but was markedly stabilized upon simultaneous overexpression of the set of Dsb proteins (DsbABCD). Whereas total HRP production increased severalfold upon overexpression of at least disulfide-bonded isomerase DsbC, maximum transport of HRP to the periplasm seemed to require overexpression of all DsbABCD proteins, suggesting that excess Dsb proteins exert synergistic effects in assisting folding and transport of HRP. Periplasmic production of HRP also increased when calcium, thought to play an essential role in folding of nascent HRP polypeptide, was added to the medium with or without Dsb overexpression. These results suggest that Dsb proteins and calcium play distinct roles in periplasmic production of HRP, presumably through facilitating correct folding. The present Dsb expression plasmids should be useful in assessing and dissecting periplasmic production of proteins that contain multiple disulfide bonds in E. coli.

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Deshmukh, Meenal, Serdar Turkarslan, Donniel Astor, Maria Valkova-Valchanova, and Fevzi Daldal. "The Dithiol:Disulfide Oxidoreductases DsbA and DsbB of Rhodobacter capsulatus Are Not Directly Involved in Cytochrome c Biogenesis, but Their Inactivation Restores the Cytochrome c Biogenesis Defect of CcdA-Null Mutants." Journal of Bacteriology 185, no. 11 (June 1, 2003): 3361–72. http://dx.doi.org/10.1128/jb.185.11.3361-3372.2003.

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ABSTRACT The cytoplasmic membrane protein CcdA and its homologues in other species, such as DsbD of Escherichia coli, are thought to supply the reducing equivalents required for the biogenesis of c-type cytochromes that occurs in the periplasm of gram-negative bacteria. CcdA-null mutants of the facultative phototroph Rhodobacter capsulatus are unable to grow under photosynthetic conditions (Ps−) and do not produce any active cytochrome c oxidase (Nadi−) due to a pleiotropic cytochrome c deficiency. However, under photosynthetic or respiratory growth conditions, these mutants revert frequently to yield Ps+ Nadi+ colonies that produce c-type cytochromes despite the absence of CcdA. Complementation of a CcdA-null mutant for the Ps+ growth phenotype was attempted by using a genomic library constructed with chromosomal DNA from a revertant. No complementation was observed, but plasmids that rescued a CcdA-null mutant for photosynthetic growth by homologous recombination were recovered. Analysis of one such plasmid revealed that the rescue ability was mediated by open reading frame 3149, encoding the dithiol:disulfide oxidoreductase DsbA. DNA sequence data revealed that the dsbA allele on the rescuing plasmid contained a frameshift mutation expected to produce a truncated, nonfunctional DsbA. Indeed, a dsbA ccdA double mutant was shown to be Ps+ Nadi+, establishing that in R. capsulatus the inactivation of dsbA suppresses the c-type cytochrome deficiency due to the absence of ccdA. Next, the ability of the wild-type dsbA allele to suppress the Ps+ growth phenotype of the dsbA ccdA double mutant was exploited to isolate dsbA-independent ccdA revertants. Sequence analysis revealed that these revertants carried mutations in dsbB and that their Ps+ phenotypes could be suppressed by the wild-type allele of dsbB. As with dsbA, a dsbB ccdA double mutant was also Ps+ Nadi+ and produced c-type cytochromes. Therefore, the absence of either DsbA or DsbB restores c-type cytochrome biogenesis in the absence of CcdA. Finally, it was also found that the DsbA-null and DsbB-null single mutants of R. capsulatus are Ps+ and produce c-type cytochromes, unlike their E. coli counterparts, but are impaired for growth under respiratory conditions. This finding demonstrates that in R. capsulatus the dithiol:disulfide oxidoreductases DsbA and DsbB are not essential for cytochrome c biogenesis even though they are important for respiration under certain conditions.

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8

Skórko-Glonek, Joanna, Anna Sobiecka-Szkatuła, and Barbara Lipińska. "Characterization of disulfide exchange between DsbA and HtrA proteins from Escherichia coli." Acta Biochimica Polonica 53, no. 3 (October 1, 2006): 585–89. http://dx.doi.org/10.18388/abp.2006_3331.

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DsbA is the major oxidase responsible for generation of disulfide bonds in proteins of E. coli envelope. In the present work we provided the first detailed characterization of disulfide exchange between DsbA and its natural substrate, HtrA protease. We demonstrated that HtrA oxidation relies on DsbA, both in vivo and in vitro. We followed the disulfide exchange between these proteins spectrofluorimetrically and found that DsbA oxidizes HtrA with a 1:1 stoichiometry. The calculated second-order apparent rate constant (kapp) of this reaction was 3.3x10(4)+/-0.6x10(4) M-1s-1. This value was significantly higher than the values obtained for nonfunctional disulfide exchanges between DsbA and DsbC or DsbD and it was comparable to the kapp values calculated for in vitro oxidation of certain non-natural DsbA substrates of eukaryotic origin.

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9

Andersen, Catherine L., Anne Matthey‐Dupraz, Dominique Missiakas, and Satish Raina. "A new Escherichia coli gene, dsbG , encodes a periplasmic protein involved in disulphide bond formation, required for recycling DsbA/DsbB and DsbC redox proteins." Molecular Microbiology 26, no. 1 (October 1997): 121–32. http://dx.doi.org/10.1046/j.1365-2958.1997.5581925.x.

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10

Chim, Nicholas, Robert Riley, Juliana The, Soyeon Im, Brent Segelke, Tim Lekin, Minmin Yu, et al. "An Extracellular Disulfide Bond Forming Protein (DsbF) from Mycobacterium tuberculosis: Structural, Biochemical, and Gene Expression Analysis." Journal of Molecular Biology 396, no. 5 (March 2010): 1211–26. http://dx.doi.org/10.1016/j.jmb.2009.12.060.

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11

Tan, Jacqueline, Ying Lu, and James C. A. Bardwell. "Mutational Analysis of the Disulfide Catalysts DsbA and DsbB." Journal of Bacteriology 187, no. 4 (February 15, 2005): 1504–10. http://dx.doi.org/10.1128/jb.187.4.1504-1510.2005.

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ABSTRACT In prokaryotes, disulfides are generated by the DsbA-DsbB system. DsbB functions to generate disulfides by quinone reduction. These disulfides are passed to the DsbA protein and then to folding proteins. To investigate the DsbA-DsbB catalytic system, we performed an in vivo selection for chromosomal dsbA and dsbB mutants. We rediscovered many residues previously shown to be important for the activity of these proteins. In addition, we obtained one novel DsbA mutant (M153R) and four novel DsbB mutants (L43P, H91Y, R133C, and L146R). We also mutated residues that are highly conserved within the DsbB family in an effort to identify residues important for DsbB function. We found classes of mutants that specifically affect the apparent Km of DsbB for either DsbA or quinones, suggesting that quinone and DsbA may interact with different regions of the DsbB protein. Our results are consistent with the interpretation that the residues Q33 and Y46 of DsbB interact with DsbA, Q95 and R48 interact with quinones, and that residue M153 of DsbA interacts with DsbB. All of these interactions could be due to direct amino acid interactions or could be indirect through, for instance, their effect on protein structure. In addition, we find that the DsbB H91Y mutant severely affects the k cat of the reaction between DsbA and DsbB and that the DsbB L43P mutant is inactive, suggesting that both L43 and H91 are important for the activity of DsbB. These experiments help to better define the residues important for the function of these two protein-folding catalysts.

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12

Yu, Jun. "Inactivation of DsbA, but Not DsbC and DsbD, Affects the Intracellular Survival and Virulence ofShigella flexneri." Infection and Immunity 66, no. 8 (August 1, 1998): 3909–17. http://dx.doi.org/10.1128/iai.66.8.3909-3917.1998.

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ABSTRACT In this study, three mutants,dsbA::kan, dsbC-kan, anddsbD-kan, of Shigella flexneri serotype 5 were constructed and characterized to investigate the role of the periplasmic thiol:disulfide oxidoreductases in pathogenicity. In gentamicin protection assays and the Serény test, thedsbA mutant showed reduced virulence while thedsbC and dsbD mutants were similar to the wild type. That inactivation of dsbA was responsible for the reduced virulence was verified by complementation with the cloned wild-type gene in in vitro and in vivo assays. Despite the changed virulence behavior, the dsbA mutant could penetrate HeLa cells 15 min postinfection, consistent with the fact that it actively secretes Ipa proteins upon Congo red induction. Furthermore, thedsbA mutant was able to produce actin comets and protrusions, indicating its capacity for intra- and intercellular spread. However, a kinetic analysis of intracellular growth showed that the dsbA mutant barely grew in HeLa cells during a 4-h infection whereas the wild type had a doubling time of 41 min. Electron microscopy analysis revealed that dsbA mutant bacteria were trapped in protrusion-derived vacuoles surrounded by double membranes, resembling an icsB mutant reported previously. Moreover, the trapped bacteria appeared to be lysed simultaneously with the double membranes, resulting in characteristic empty vacuoles in the host cell cytosol. Thus, the attenuation mechanism for dsbAmutant appears to be more complicated than was previously suggested.

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Raczko, Anna M., Janusz M. Bujnicki, Marcin Pawłowski, Renata Godlewska, Magdalena Lewandowska, and Elżbieta K. Jagusztyn-Krynicka. "Characterization of new DsbB-like thiol-oxidoreductases of Campylobacter jejuni and Helicobacter pylori and classification of the DsbB family based on phylogenomic, structural and functional criteria." Microbiology 151, no. 1 (January 1, 2005): 219–31. http://dx.doi.org/10.1099/mic.0.27483-0.

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In Gram-negative bacterial cells, disulfide bond formation occurs in the oxidative environment of the periplasm and is catalysed by Dsb (disulfide bond) proteins found in the periplasm and in the inner membrane. In this report the identification of a new subfamily of disulfide oxidoreductases encoded by a gene denoted dsbI, and functional characterization of DsbI proteins from Campylobacter jejuni and Helicobacter pylori, as well as DsbB from C. jejuni, are described. The N-terminal domain of DsbI is related to DsbB proteins and comprises five predicted transmembrane segments, while the C-terminal domain is predicted to locate to the periplasm and to fold into a β-propeller structure. The dsbI gene is co-transcribed with a small ORF designated dba ( dsbI-accessory). Based on a series of deletion and complementation experiments it is proposed that DsbB can complement the lack of DsbI but not the converse. In the presence of DsbB, the activity of DsbI was undetectable, hence it probably acts only on a subset of possible substrates of DsbB. To reconstruct the principal events in the evolution of DsbB and DsbI proteins, sequences of all their homologues identifiable in databases were analysed. In the course of this study, previously undetected variations on the common thiol-oxidoreductase theme were identified, such as development of an additional transmembrane helix and loss or migration of the second pair of Cys residues between two distinct periplasmic loops. In conjunction with the experimental characterization of two members of the DsbI lineage, this analysis has resulted in the first comprehensive classification of the DsbB/DsbI family based on structural, functional and evolutionary criteria.

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Kadokura, Hiroshi, Lorenzo Nichols, and Jon Beckwith. "Mutational Alterations of the Key cis Proline Residue That Cause Accumulation of Enzymatic Reaction Intermediates of DsbA, a Member of the Thioredoxin Superfamily." Journal of Bacteriology 187, no. 4 (February 15, 2005): 1519–22. http://dx.doi.org/10.1128/jb.187.4.1519-1522.2005.

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ABSTRACT The DsbA-DsbB pathway introduces disulfide bonds into newly translocated proteins. Conversion of the conserved cis proline 151 of DsbA to several hydrophilic residues results in accumulation of mixed disulfides between DsbA and its dedicated oxidant, DsbB. However, only a proline-to-threonine change causes accumulation of mixed disulfides of DsbA with its substrates.

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Seo, Sang-Woo, Somi Yun, Myung-Gyu Kim, Mankyu Sung, and Yejin Kim. "Screen-Based Sports Simulation Using Acoustic Source Localization." Applied Sciences 9, no. 15 (July 24, 2019): 2970. http://dx.doi.org/10.3390/app9152970.

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In this paper, we introduce a novel acoustic source localization in a three-dimensional (3D) space, based on a direction estimation technique. Assuming an acoustic source at a distance from adjacent microphones, its waves spread in a planar form called a planar wavefront. In our system, the directions and steering angles between the acoustic source and the microphone array are estimated based on a planar wavefront model using a delay and sum beamforming (DSBF) system and an array of two-dimensional (2D) microelectromechanical system (MEMS) microphones. The proposed system is designed with parallel processing hardware for real-time performance and implemented using a cost-effective field programmable gate array (FPGA) and a micro control unit (MCU). As shown in the experimental results, the localization errors of the proposed system were less than 3 cm when an impulsive acoustic source was generated over 1 m away from the microphone array, which is comparable to a position-based system with reduced computational complexity. On the basis of the high accuracy and real-time performance of localizing an impulsive acoustic source, such as striking a ball, the proposed system can be applied to screen-based sports simulation.

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Totsika, Makrina, Begoña Heras, Daniël J. Wurpel, and Mark A. Schembri. "Characterization of Two Homologous Disulfide Bond Systems Involved in Virulence Factor Biogenesis in Uropathogenic Escherichia coli CFT073." Journal of Bacteriology 191, no. 12 (April 17, 2009): 3901–8. http://dx.doi.org/10.1128/jb.00143-09.

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ABSTRACT Disulfide bond (DSB) formation is catalyzed by disulfide bond proteins and is critical for the proper folding and functioning of secreted and membrane-associated bacterial proteins. Uropathogenic Escherichia coli (UPEC) strains possess two paralogous disulfide bond systems: the well-characterized DsbAB system and the recently described DsbLI system. In the DsbAB system, the highly oxidizing DsbA protein introduces disulfide bonds into unfolded polypeptides by donating its redox-active disulfide and is in turn reoxidized by DsbB. DsbA has broad substrate specificity and reacts readily with reduced unfolded proteins entering the periplasm. The DsbLI system also comprises a functional redox pair; however, DsbL catalyzes the specific oxidative folding of the large periplasmic enzyme arylsulfate sulfotransferase (ASST). In this study, we characterized the DsbLI system of the prototypic UPEC strain CFT073 and examined the contributions of the DsbAB and DsbLI systems to the production of functional flagella as well as type 1 and P fimbriae. The DsbLI system was able to catalyze disulfide bond formation in several well-defined DsbA targets when provided in trans on a multicopy plasmid. In a mouse urinary tract infection model, the isogenic dsbAB deletion mutant of CFT073 was severely attenuated, while deletion of dsbLI or assT did not affect colonization.

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Bessette, Paul H., Ji Qiu, James C. A. Bardwell, James R. Swartz, and George Georgiou. "Effect of Sequences of the Active-Site Dipeptides of DsbA and DsbC on In Vivo Folding of Multidisulfide Proteins inEscherichia coli." Journal of Bacteriology 183, no. 3 (February 1, 2001): 980–88. http://dx.doi.org/10.1128/jb.183.3.980-988.2001.

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ABSTRACT We have examined the role of the active-site CXXC central dipeptides of DsbA and DsbC in disulfide bond formation and isomerization in the Escherichia coli periplasm. DsbA active-site mutants with a wide range of redox potentials were expressed either from the trc promoter on a multicopy plasmid or from the endogenous dsbA promoter by integration of the respective alleles into the bacterial chromosome. ThedsbA alleles gave significant differences in the yield of active murine urokinase, a protein containing 12 disulfides, including some that significantly enhanced urokinase expression over that allowed by wild-type DsbA. No direct correlation between the in vitro redox potential of dsbA variants and the urokinase yield was observed. These results suggest that the active-site CXXC motif of DsbA can play an important role in determining the folding of multidisulfide proteins, in a way that is independent from DsbA's redox potential. However, under aerobic conditions, there was no significant difference among the DsbA mutants with respect to phenotypes depending on the oxidation of proteins with few disulfide bonds. The effect of active-site mutations in the CXXC motif of DsbC on disulfide isomerization in vivo was also examined. A library of DsbC expression plasmids with the active-site dipeptide randomized was screened for mutants that have increased disulfide isomerization activity. A number of DsbC mutants that showed enhanced expression of a variant of human tissue plasminogen activator as well as mouse urokinase were obtained. These DsbC mutants overwhelmingly contained an aromatic residue at the C-terminal position of the dipeptide, whereas the N-terminal residue was more diverse. Collectively, these data indicate that the active sites of the soluble thiol- disulfide oxidoreductases can be modulated to enhance disulfide isomerization and protein folding in the bacterial periplasmic space.

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Kishigami, Satoshi, Eiko Kanaya, Masakazu Kikuchi, and Koreaki Ito. "DsbA-DsbB Interaction through Their Active Site Cysteines." Journal of Biological Chemistry 270, no. 29 (July 21, 1995): 17072–74. http://dx.doi.org/10.1074/jbc.270.29.17072.

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Feissner, Robert E., Caroline S. Beckett, Jennifer A. Loughman, and Robert G. Kranz. "Mutations in Cytochrome Assembly and Periplasmic Redox Pathways in Bordetella pertussis." Journal of Bacteriology 187, no. 12 (June 15, 2005): 3941–49. http://dx.doi.org/10.1128/jb.187.12.3941-3949.2005.

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ABSTRACT Transposon mutagenesis of Bordetella pertussis was used to discover mutations in the cytochrome c biogenesis pathway called system II. Using a tetramethyl-p-phenylenediamine cytochrome c oxidase screen, 27 oxidase-negative mutants were isolated and characterized. Nine mutants were still able to synthesize c-type cytochromes and possessed insertions in the genes for cytochrome c oxidase subunits (ctaC, -D, and -E), heme a biosynthesis (ctaB), assembly of cytochrome c oxidase (sco2), or ferrochelatase (hemZ). Eighteen mutants were unable to synthesize all c-type cytochromes. Seven of these had transposons in dipZ (dsbD), encoding the transmembrane thioreduction protein, and all seven mutants were corrected for cytochrome c assembly by exogenous dithiothreitol, which was consistent with the cytochrome c cysteinyl residues of the CXXCH motif requiring periplasmic reduction. The remaining 11 insertions were located in the ccsBA operon, suggesting that with the appropriate thiol-reducing environment, the CcsB and CcsA proteins comprise the entire system II biosynthetic pathway. Antiserum to CcsB was used to show that CcsB is absent in ccsA mutants, providing evidence for a stable CcsA-CcsB complex. No mutations were found in the genes necessary for disulfide bond formation (dsbA or dsbB). To examine whether the periplasmic disulfide bond pathway is required for cytochrome c biogenesis in B. pertussis, a targeted knockout was made in dsbB. The DsbB− mutant makes holocytochromes c like the wild type does and secretes and assembles the active periplasmic alkaline phosphatase. A dipZ mutant is not corrected by a dsbB mutation. Alternative mechanisms to oxidize disulfides in B. pertussis are analyzed and discussed.

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Jiang, Bo-Le, Jiao Liu, Li-Feng Chen, Ying-Ying Ge, Xiao-Hong Hang, Yong-Qiang He, Dong-Jie Tang, Guang-Tao Lu, and Ji-Liang Tang. "DsbB Is Required for the Pathogenesis Process of Xanthomonas campestris pv. campestris." Molecular Plant-Microbe Interactions® 21, no. 8 (August 2008): 1036–45. http://dx.doi.org/10.1094/mpmi-21-8-1036.

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The DsbA/DsbB oxidation pathway is one of the two pathways that catalyze disulfide bond formation of proteins in the periplasm of gram-negative bacteria. It has been demonstrated that DsbA is essential for multiple virulence factors of several animal bacterial pathogens. In this article, we present genetic evidence to show that the open reading frame XC_3314 encodes a DsbB protein that is involved in disulfide bond formation in periplasm of Xanthomonas campestris pv. campestris, the causative agent of crucifer black rot disease. The dsbB mutant of X. campestris pv. campestris exhibited attenuation in virulence, hypersensitive response, cell motility, and bacterial growth in planta. Furthermore, mutation in the dsbB gene resulted in ineffective type II and type III secretion systems as well as flagellar assembly. These findings reveal that DsbB is required for the pathogenesis process of X. campestris pv. campestris.

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Cho, Seung-Hyun, and Jon Beckwith. "Mutations of the Membrane-Bound Disulfide Reductase DsbD That Block Electron Transfer Steps from Cytoplasm to Periplasm in Escherichia coli." Journal of Bacteriology 188, no. 14 (July 15, 2006): 5066–76. http://dx.doi.org/10.1128/jb.00368-06.

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ABSTRACT The cytoplasmic membrane protein DsbD keeps the periplasmic disulfide isomerase DsbC reduced, using the cytoplasmic reducing power of thioredoxin. DsbD contains three domains, each containing two reactive cysteines. One membrane-embedded domain, DsbDβ, transfers electrons from thioredoxin to the carboxy-terminal thioredoxin-like periplasmic domain DsbDγ. To evaluate the role of conserved amino acid residues in DsbDβ in the electron transfer process, we substituted alanines for each of 19 conserved amino acid residues and assessed the in vivo redox states of DsbC and DsbD. The mutant DsbDs of 11 mutants which caused defects in DsbC reduction showed relatively oxidized redox states. To analyze the redox state of each DsbD domain, we constructed a thrombin-cleavable DsbD (DsbDTH) from which we could generate all three domains as separate polypeptide chains by thrombin treatment in vitro. We divided the mutants with strong defects into two classes. The first mutant class consists of mutant DsbDβ proteins that cannot receive electrons from cytoplasmic thioredoxin, resulting in a DsbD that has all six of its cysteines disulfide bonded. The second mutant class represents proteins in which the transfer of electrons from DsbDβ to DsbDγ appears to be blocked. This class includes the mutant with the most clear-cut defect, P284A. We relate the properties of the mutants to the positions of the amino acids in the structure of DsbD and discuss mechanisms that would interfere with the electron transfer process.

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Premkumar, Lakshmanane, Begoña Heras, Wilko Duprez, Patricia Walden, Maria Halili, Fabian Kurth, David P. Fairlie, and Jennifer L. Martin. "Rv2969c, essential for optimal growth inMycobacterium tuberculosis, is a DsbA-like enzyme that interacts with VKOR-derived peptides and has atypical features of DsbA-like disulfide oxidases." Acta Crystallographica Section D Biological Crystallography 69, no. 10 (September 20, 2013): 1981–94. http://dx.doi.org/10.1107/s0907444913017800.

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The bacterial disulfide machinery is an attractive molecular target for developing new antibacterials because it is required for the production of multiple virulence factors. The archetypal disulfide oxidase proteins inEscherichia coli(Ec) are DsbA and DsbB, which together form a functional unit: DsbA introduces disulfides into folding proteins and DsbB reoxidizes DsbA to maintain it in the active form. InMycobacterium tuberculosis(Mtb), no DsbB homologue is encoded but a functionally similar but structurally divergent protein, MtbVKOR, has been identified. Here, the Mtb protein Rv2969c is investigated and it is shown that it is the DsbA-like partner protein of MtbVKOR. It is found that it has the characteristic redox features of a DsbA-like protein: a highly acidic catalytic cysteine, a highly oxidizing potential and a destabilizing active-site disulfide bond. Rv2969c also has peptide-oxidizing activity and recognizes peptide segments derived from the periplasmic loops of MtbVKOR. Unlike the archetypal EcDsbA enzyme, Rv2969c has little or no activity in disulfide-reducing and disulfide-isomerase assays. The crystal structure of Rv2969c reveals a canonical DsbA fold comprising a thioredoxin domain with an embedded helical domain. However, Rv2969c diverges considerably from other DsbAs, including having an additional C-terminal helix (H8) that may restrain the mobility of the catalytic helix H1. The enzyme is also characterized by a very shallow hydrophobic binding surface and a negative electrostatic surface potential surrounding the catalytic cysteine. The structure of Rv2969c was also used to model the structure of a paralogous DsbA-like domain of the Ser/Thr protein kinase PknE. Together, these results show that Rv2969c is a DsbA-like protein with unique properties and a limited substrate-binding specificity.

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Urban, Andreas, Martina Leipelt, Thorsten Eggert, and Karl-Erich Jaeger. "DsbA and DsbC Affect Extracellular Enzyme Formation in Pseudomonas aeruginosa." Journal of Bacteriology 183, no. 2 (January 15, 2001): 587–96. http://dx.doi.org/10.1128/jb.183.2.587-596.2001.

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ABSTRACT DsbA and DsbC proteins involved in the periplasmic formation of disulfide bonds in Pseudomonas aeruginosa were identified and shown to play an important role for the formation of extracellular enzymes. Mutants deficient in either dsbA ordsbC or both genes were constructed, and extracellular elastase, alkaline phosphatase, and lipase activities were determined. The dsbA mutant no longer produced these enzymes, whereas the lipase activity was doubled in the dsbC mutant. Also, extracellar lipase production was severely reduced in a P. aeruginosa dsbA mutant in which an inactive DsbA variant carrying the mutation C34S was expressed. Even when the lipase genelipA was constitutively expressed in trans in alipA dsbA double mutant, lipase activity in cell extracts and culture supernatants was still reduced to about 25%. Interestingly, the presence of dithiothreitol in the growth medium completely inhibited the formation of extracellular lipase whereas the addition of dithiothreitol to a cell-free culture supernatant did not affect lipase activity. We conclude that the correct formation of the disulfide bond catalyzed in vivo by DsbA is necessary to stabilize periplasmic lipase. Such a stabilization is the prerequisite for efficient secretion using the type II pathway.

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Goldstone, D., P. W. Haebel, F. Katzen, M. W. Bader, J. C. A. Bardwell, J. Beckwith, and P. Metcalf. "DsbC activation by the N-terminal domain of DsbD." Proceedings of the National Academy of Sciences 98, no. 17 (August 7, 2001): 9551–56. http://dx.doi.org/10.1073/pnas.171315498.

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Panchakshari, Rohit A., Xuefei Zhang, Vipul Kumar, Zhou Du, Pei-Chi Wei, Jennifer Kao, Junchao Dong, and Frederick W. Alt. "DNA double-strand break response factors influence end-joining features of IgH class switch and general translocation junctions." Proceedings of the National Academy of Sciences 115, no. 4 (January 8, 2018): 762–67. http://dx.doi.org/10.1073/pnas.1719988115.

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Ig heavy chain (IgH) class switch recombination (CSR) in B lymphocytes switches IgH constant regions to change antibody functions. CSR is initiated by DNA double-strand breaks (DSBs) within a donor IgH switch (S) region and a downstream acceptor S region. CSR is completed by fusing donor and acceptor S region DSB ends by classical nonhomologous end-joining (C-NHEJ) and, in its absence, by alternative end-joining that is more biased to use longer junctional microhomologies (MHs). Deficiency for DSB response (DSBR) factors, including ataxia telangiectasia-mutated (ATM) and 53BP1, variably impair CSR end-joining, with 53BP1 deficiency having the greatest impact. However, studies of potential impact of DSBR factor deficiencies on MH-mediated CSR end-joining have been technically limited. We now use a robust DSB joining assay to elucidate impacts of deficiencies for DSBR factors on CSR and chromosomal translocation junctions in primary mouse B cells and CH12F3 B-lymphoma cells. Compared with wild-type, CSR and c-myc to S region translocation junctions in the absence of 53BP1, and, to a lesser extent, other DSBR factors, have increased MH utilization; indeed, 53BP1-deficient MH profiles resemble those associated with C-NHEJ deficiency. However, translocation junctions between c-myc DSB and general DSBs genome-wide are not MH-biased in ATM-deficient versus wild-type CH12F3 cells and are less biased in 53BP1- and C-NHEJ−deficient cells than CSR junctions or c-myc to S region translocation junctions. We discuss potential roles of DSBR factors in suppressing increased MH-mediated DSB end-joining and features of S regions that may render their DSBs prone to MH-biased end-joining in the absence of DSBR factors.

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Puts, Gemma, Stuart Jarrett, Mary Leonard, Nicolette Matsangos, Devin Snyder, Ying Wang, Richard Vincent, et al. "Metastasis Suppressor NME1 Modulates Choice of Double-Strand Break Repair Pathways in Melanoma Cells by Enhancing Alternative NHEJ while Inhibiting NHEJ and HR." International Journal of Molecular Sciences 21, no. 16 (August 17, 2020): 5896. http://dx.doi.org/10.3390/ijms21165896.

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Reduced NME1 expression in melanoma cell lines, mouse models of melanoma, and melanoma specimens in human patients is associated with increased metastatic activity. Herein, we investigate the role of NME1 in repair of double-stranded breaks (DSBs) and choice of double-strand break repair (DSBR) pathways in melanoma cells. Using chromatin immunoprecipitation, NME1 was shown to be recruited rapidly and directly to DSBs generated by the homing endonuclease I-PpoI. NME1 was recruited to DSBs within 30 min, in concert with recruitment of ataxia-telangiectasia mutated (ATM) protein, an early step in DSBR complex formation, as well as loss of histone 2B. NME1 was detected up to 5 kb from the break site after DSB induction, suggesting a role in extending chromatin reorganization away from the repair site. shRNA-mediated silencing of NME1 expression led to increases in the homologous recombination (HR) and non-homologous end-joining (NHEJ) pathways of double-strand break repair (DSBR), and reduction in the low fidelity, alternative-NHEJ (A-NHEJ) pathway. These findings suggest low expression of NME1 drives DSBR towards higher fidelity pathways, conferring enhanced genomic stability necessary for rapid and error-free proliferation in invasive and metastatic cells. The novel mechanism highlighted in the current study appears likely to impact metastatic potential and therapy-resistance in advanced melanoma and other cancers.

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Kimball, Richard A., Laetitia Martin, and Milton H. Saier Jr. "Reversing Transmembrane Electron Flow: The DsbD and DsbB Protein Families." Journal of Molecular Microbiology and Biotechnology 5, no. 3 (2003): 133–49. http://dx.doi.org/10.1159/000070263.

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Joly, John C., and James R. Swartz. "In Vitroandin VivoRedox States of theEscherichia coliPeriplasmic Oxidoreductases DsbA and DsbC." Biochemistry 36, no. 33 (August 1997): 10067–72. http://dx.doi.org/10.1021/bi9707739.

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Bushweller, John H. "Protein Disulfide Exchange by the Intramembrane Enzymes DsbB, DsbD, and CcdA." Journal of Molecular Biology 432, no. 18 (August 2020): 5091–103. http://dx.doi.org/10.1016/j.jmb.2020.04.008.

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Inaba, Kenji, and Koreaki Ito. "Structure and mechanisms of the DsbB–DsbA disulfide bond generation machine." Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 1783, no. 4 (April 2008): 520–29. http://dx.doi.org/10.1016/j.bbamcr.2007.11.006.

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Elton, Trevor C., Samantha J. Holland, Laura S. Frost, and Bart Hazes. "F-Like Type IV Secretion Systems Encode Proteins with Thioredoxin Folds That Are Putative DsbC Homologues." Journal of Bacteriology 187, no. 24 (December 15, 2005): 8267–77. http://dx.doi.org/10.1128/jb.187.24.8267-8277.2005.

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ABSTRACT F and R27 are conjugative plasmids of enteric bacteria belonging to the IncF and IncHI1 plasmid incompatibility groups, respectively. Based on sequence analysis, two genes of the F transfer region, traF and trbB, and three genes of the R27 transfer region, trhF, dsbC, and htdT, are predicted to encode periplasmic proteins containing a C-terminal thioredoxin fold. The C-X-X-C active-site motif of thioredoxins is present in all of these proteins except TraFF. Escherichia coli carrying a dsbA mutation, which is deficient in disulfide bond formation, cannot synthesize pili and exhibits hypersensitivity to dithiothreitol (DTT) as monitored by mating ability. Overproduction of the E. coli disulfide bond isomerase DsbC, TrbBF, DsbCR27, or HtdTR27, but not TraFF or TrhFR27, reverses this hypersensitivity to DTT. Site-directed mutagenesis established that the C-X-X-C motif was necessary for this activity. Secretion into the periplasm of the C-terminal regions of TrbBF and DsbCR27, containing putative thioredoxin folds, but not TrhFR27, partially complemented the host dsbA mutation. A trbBF deletion mutant showed a 10-fold-lower mating efficiency in an E. coli dsbC null strain but had no phenotype in wild-type E. coli, suggesting redundancy in function between TrbBF and E. coli DsbC. Our results indicate that TrbBF, DsbCR27, and HtdTR27 are putative disulfide bond isomerases for their respective transfer systems. TraFF is essential for conjugation but appears to have a function other than disulfide bond chemistry.

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Bader, M. W. "Turning a disulfide isomerase into an oxidase: DsbC mutants that imitate DsbA." EMBO Journal 20, no. 7 (April 1, 2001): 1555–62. http://dx.doi.org/10.1093/emboj/20.7.1555.

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Inaba, K. "Structure and mechanism of the DsbB-DsbA protein disulfide generation system inE. coli." Acta Crystallographica Section A Foundations of Crystallography 64, a1 (August 23, 2008): C111—C112. http://dx.doi.org/10.1107/s0108767308096426.

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Sperling, Lindsay J., Ming Tang, Deborah A. Berthold, Anna E. Nesbitt, Robert B. Gennis, and Chad M. Rienstra. "Solid-State NMR Study of a 41 kDa Membrane Protein Complex DsbA/DsbB." Journal of Physical Chemistry B 117, no. 20 (May 9, 2013): 6052–60. http://dx.doi.org/10.1021/jp400795d.

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35

Manchope, Marília F., Mariana M. Bertozzi, Sergio M. Borghi, Cíntia L. Handa, Mariana A. Queiroz-Cancian, Camila R. Ferraz, Sandra S. Mizokami, et al. "Fermented (By Monascus purpureus or Aspergillus oryzae) and Non-Fermented Defatted Soybean Flour Extracts: Biological Insight and Mechanism Differences in Inflammatory Pain and Peritonitis." Fermentation 9, no. 2 (February 11, 2023): 167. http://dx.doi.org/10.3390/fermentation9020167.

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Background: Monascus purpureus and Aspergillus oryzae have been used to ferment defatted soybean flour (DSF: DSFF-Mp and DSSF-Ao, respectively) extract, improving antioxidant availability and conversion of the glycosylated isoflavones to aglycones. The aim of the present study was to evaluate the biological activity of fermented and non-fermented DSF extracts in pain and inflammation, which has not yet been explored. Methods: Phenolic compounds of extracts were determined. Non-fermented DSF (DSF-Non), DSFF-Mp, and DSFF-Ao (10–100 mg/kg) were administrated i.p., 30 min before i.pl. or i.p. carrageenan stimulus. Mechanical and thermal hyperalgesia, edema, histopathology, leukocyte recruitment, and oxidative stress in the paw tissue, and inflammatory cell recruitment, NFκB activation, and cytokine production were assessed in the peritoneum. Stomach and kidney toxicity were evaluated. Results: DSF-Non, DSFF-Mp, and DSFF-Ao extracts inhibited mechanical and thermal hyperalgesia, paw edema, histopathology, neutrophil recruitment, and oxidative stress, as well as inhibited peritoneal leukocyte recruitment. DSF-Non increased IL-10, and DSFF-Ao reduced IL-33 levels. DSFF-Mp increased IL-10 and reduced IL-33 production, and NFκB activation in CD45+ cells, without inducing toxicity. Conclusions: The present data reveal for the first time that fermented/non-fermented DSF extracts are analgesic and anti-inflammatory, showing differences in the mechanism of action depending on fungi applied for fermentation.

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REID, Eleanor, Jeff COLE, and Deborah J. EAVES. "The Escherichia coli CcmG protein fulfils a specific role in cytochrome c assembly." Biochemical Journal 355, no. 1 (February 26, 2001): 51–58. http://dx.doi.org/10.1042/bj3550051.

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In Escherichia coli K-12, c-type cytochromes are synthesized only during anaerobic growth with trimethylamine-N-oxide, nitrite or low concentrations of nitrate as the terminal electron acceptor. A thioredoxin-like protein, CcmG, is one of 12 proteins required for their assembly in the periplasm. Its postulated function is to reduce disulphide bonds formed between correctly paired cysteine residues in the cytochrome c apoproteins prior to haem attachment by CcmF and CcmH. We report that loss of CcmG synthesis by mutation was not compensated by a second mutation in disulphide-bond-forming proteins, DsbA or DsbB, or by the chemical reductant, 2-mercaptoethanesulphonic acid. An anti-CcmG polyclonal antibody was used in Western-blot analysis to probe the redox state of CcmG in mutants defective in the synthesis of other proteins essential for cytochrome c assembly. The oxidized form of CcmG accumulated not only in trxA or dipZ mutants defective in the transfer of electrons from the cytoplasm for disulphide isomerization and reduction reactions in the periplasm, but also in ccmF and ccmH mutants. The requirement of both CcmF and CcmH for the reduction of the disulphide bond in CcmG indicates that CcmG functions later than CcmF and CcmH in cytochrome c assembly, rather than in electron transfer from the membrane-associated DipZ (also known as DsbD) to CcmH. The data support a model proposed by others in which CcmG catalyses one of the last reactions specific to cytochrome c assembly.

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Debarbieux, Laurent, and Jon Beckwith. "On the Functional Interchangeability, Oxidant versus Reductant, of Members of the Thioredoxin Superfamily." Journal of Bacteriology 182, no. 3 (February 1, 2000): 723–27. http://dx.doi.org/10.1128/jb.182.3.723-727.2000.

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ABSTRACT Escherichia coli thioredoxin 1 has been characterized in vivo and in vitro as one of the most efficient reductants of disulfide bonds. Nevertheless, under some conditions, thioredoxin 1 can also act in vivo as an oxidant, promoting formation of disulfide bonds in the cytoplasm (E. J. Stewart, F. Åslund, and J. Beckwith, EMBO J. 17:5543–5550, 1998). We recently showed that when a signal sequence is attached to thioredoxin 1 it is exported to the periplasm, where it can also act as an oxidant, replacing the normal periplasmic catalyst of disulfide bond formation, DsbA, in oxidizing cell envelope proteins (L. Debarbieux and J. Beckwith, Proc. Natl. Acad. Sci. USA 95:10751–10756, 1998). Here we report pulse-chase studies of the efficiency of disulfide bond formation in strains exporting thioredoxin 1 and more-oxidizing variants of it. While the exported thioredoxin 1 itself substantially speeds up the kinetics of disulfide bond formation, a version of this protein containing the DsbA active site exhibits kinetics that are indistinguishable from those of the DsbA protein itself. Further, we confirm the findings of Jonda et al. (S. Jonda, M. Huber-Wunderlich, R. Glockshuber, and E. Mössner, EMBO J. 18:3271–3281, 1999), who found that DsbB is responsible for the oxidation of exported thioredoxin 1, and we report the detection of a disulfide-bonded DsbB-thioredoxin 1 complex. Finally, we have found that under conditions of high-level expression of exported thioredoxin 1, the protein can act as both an oxidant and a reductant.

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Shevchik, Vladimir E., Isabelle Bortoli-Gernnan, Janine Robert-Baudouy, Sandrine Robinet, Frederic Barras, and Guy Condemine. "Differential effect of dsbA and dsbC mutations on extracellular enzyme secretion in Erwinia chrysanthemi." Molecular Microbiology 16, no. 4 (May 1995): 745–53. http://dx.doi.org/10.1111/j.1365-2958.1995.tb02435.x.

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39

Inaba, K. "Paradoxical redox properties of DsbB and DsbA in the protein disulfide-introducing reaction cascade." EMBO Journal 21, no. 11 (June 3, 2002): 2646–54. http://dx.doi.org/10.1093/emboj/21.11.2646.

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40

Yeh, Shin-Mei, Nayden Koon, Christopher Squire, and Peter Metcalf. "Structures of the dimerization domains of theEscherichia colidisulfide-bond isomerase enzymes DsbC and DsbG." Acta Crystallographica Section D Biological Crystallography 63, no. 4 (March 16, 2007): 465–71. http://dx.doi.org/10.1107/s0907444907003320.

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41

Sone, Michio, Yoshinori Akiyama, and Koreaki Ito. "Differentialin VivoRoles Played by DsbA and DsbC in the Formation of Protein Disulfide Bonds." Journal of Biological Chemistry 272, no. 16 (April 18, 1997): 10349–52. http://dx.doi.org/10.1074/jbc.272.16.10349.

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42

Inaba, Kenji, Satoshi Murakami, Mamoru Suzuki, Atsushi Nakagawa, Eiki Yamashita, Kengo Okada, and Koreaki Ito. "Crystal Structure of the DsbB-DsbA Complex Reveals a Mechanism of Disulfide Bond Generation." Cell 127, no. 4 (November 2006): 789–801. http://dx.doi.org/10.1016/j.cell.2006.10.034.

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43

Inaba, Kenji, Yoh-hei Takahashi, and Koreaki Ito. "DsbB Elicits a Red-shift of Bound Ubiquinone during the Catalysis of DsbA Oxidation." Journal of Biological Chemistry 279, no. 8 (November 20, 2003): 6761–68. http://dx.doi.org/10.1074/jbc.m310765200.

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Bashirova, Anna, Subrata Pramanik, Pavel Volkov, Aleksandra Rozhkova, Vitaly Nemashkalov, Ivan Zorov, Alexander Gusakov, Arkady Sinitsyn, Ulrich Schwaneberg, and Mehdi Davari. "Disulfide Bond Engineering of an Endoglucanase from Penicillium verruculosum to Improve Its Thermostability." International Journal of Molecular Sciences 20, no. 7 (March 30, 2019): 1602. http://dx.doi.org/10.3390/ijms20071602.

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Endoglucanases (EGLs) are important components of multienzyme cocktails used in the production of a wide variety of fine and bulk chemicals from lignocellulosic feedstocks. However, a low thermostability and the loss of catalytic performance of EGLs at industrially required temperatures limit their commercial applications. A structure-based disulfide bond (DSB) engineering was carried out in order to improve the thermostability of EGLII from Penicillium verruculosum. Based on in silico prediction, two improved enzyme variants, S127C-A165C (DSB2) and Y171C-L201C (DSB3), were obtained. Both engineered enzymes displayed a 15–21% increase in specific activity against carboxymethylcellulose and β-glucan compared to the wild-type EGLII (EGLII-wt). After incubation at 70 °C for 2 h, they retained 52–58% of their activity, while EGLII-wt retained only 38% of its activity. At 80 °C, the enzyme-engineered forms retained 15–22% of their activity after 2 h, whereas EGLII-wt was completely inactivated after the same incubation time. Molecular dynamics simulations revealed that the introduced DSB rigidified a global structure of DSB2 and DSB3 variants, thus enhancing their thermostability. In conclusion, this work provides an insight into DSB protein engineering as a potential rational design strategy that might be applicable for improving the stability of other enzymes for industrial applications.

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45

Kadokura, H. "Four cysteines of the membrane protein DsbB act in concert to oxidize its substrate DsbA." EMBO Journal 21, no. 10 (May 15, 2002): 2354–63. http://dx.doi.org/10.1093/emboj/21.10.2354.

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Halili, Maria A., Prabhakar Bachu, Fredrik Lindahl, Chérine Bechara, Biswaranjan Mohanty, Robert C. Reid, Martin J. Scanlon, Carol V. Robinson, David P. Fairlie, and Jennifer L. Martin. "Small Molecule Inhibitors of Disulfide Bond Formation by the Bacterial DsbA–DsbB Dual Enzyme System." ACS Chemical Biology 10, no. 4 (January 27, 2015): 957–64. http://dx.doi.org/10.1021/cb500988r.

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47

Yazawa, Kenjiro, Hiroyuki Furusawa, and Yoshio Okahata. "Mechanism of Thiol–Disulfide Exchange Reactions between DsbA and DsbB over a Wide pH Range." Chemistry Letters 42, no. 3 (March 5, 2013): 241–43. http://dx.doi.org/10.1246/cl.2013.241.

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48

Blasiak, Janusz, Joanna Szczepańska, Anna Sobczuk, Michal Fila, and Elzbieta Pawlowska. "RIF1 Links Replication Timing with Fork Reactivation and DNA Double-Strand Break Repair." International Journal of Molecular Sciences 22, no. 21 (October 23, 2021): 11440. http://dx.doi.org/10.3390/ijms222111440.

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Replication timing (RT) is a cellular program to coordinate initiation of DNA replication in all origins within the genome. RIF1 (replication timing regulatory factor 1) is a master regulator of RT in human cells. This role of RIF1 is associated with binding G4-quadruplexes and changes in 3D chromatin that may suppress origin activation over a long distance. Many effects of RIF1 in fork reactivation and DNA double-strand (DSB) repair (DSBR) are underlined by its interaction with TP53BP1 (tumor protein p53 binding protein). In G1, RIF1 acts antagonistically to BRCA1 (BRCA1 DNA repair associated), suppressing end resection and homologous recombination repair (HRR) and promoting non-homologous end joining (NHEJ), contributing to DSBR pathway choice. RIF1 is an important element of intra-S-checkpoints to recover damaged replication fork with the involvement of HRR. High-resolution microscopic studies show that RIF1 cooperates with TP53BP1 to preserve 3D structure and epigenetic markers of genomic loci disrupted by DSBs. Apart from TP53BP1, RIF1 interact with many other proteins, including proteins involved in DNA damage response, cell cycle regulation, and chromatin remodeling. As impaired RT, DSBR and fork reactivation are associated with genomic instability, a hallmark of malignant transformation, RIF1 has a diagnostic, prognostic, and therapeutic potential in cancer. Further studies may reveal other aspects of common regulation of RT, DSBR, and fork reactivation by RIF1.

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Carrer, D., S. Lafont, J. L. Roujean, J. C. Calvet, C. Meurey, P. Le Moigne, and I. F. Trigo. "Incoming Solar and Infrared Radiation Derived from METEOSAT: Impact on the Modeled Land Water and Energy Budget over France." Journal of Hydrometeorology 13, no. 2 (April 1, 2012): 504–20. http://dx.doi.org/10.1175/jhm-d-11-059.1.

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Abstract The Land Surface Analysis Satellite Applications Facility (LSA SAF) project radiation fluxes, derived from the Meteosat Second Generation (MSG) geostationary satellite, were used in the Interactions between Soil, Biosphere, and Atmosphere (ISBA) land surface model (LSM), which is a component of the Surface Externalisée (SURFEX) modeling platform. The Système d’Analyze Fournissant des Renseignements Atmosphériques à la Neige (SAFRAN) atmospheric analysis provides high-resolution atmospheric variables used to drive LSMs over France. The impact of using the incoming solar and infrared radiation fluxes [downwelling surface shortwave (DSSF) and longwave (DSLF), respectively] from either SAFRAN or LSA SAF, in ISBA, was investigated over France for 2006. In situ observations from the Flux Network (FLUXNET) were used for the verification. Daily differences between SAFRAN and LSA SAF radiation fluxes averaged over the whole year 2006 were 3.75 and 2.61 W m−2 for DSSF and DSLF, respectively, representing 2.5% and 0.8% of their average values. The LSA SAF incoming solar radiation presented a better agreement with in situ measurements at six FLUXNET stations than the SAFRAN analysis. The bias and standard deviation of differences were reduced by almost 50%. The added value of the LSA SAF products was assessed with the simulated surface temperature, soil moisture, and the water and energy fluxes. The latter quantities were improved by the use of LSA SAF satellite estimates. As many areas lack a high-resolution meteorological analysis, the LSA SAF radiative products provide new and valuable information.

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Sone, Michio, Yoshinori Akiyama, and Koreaki Ito. "Differential in vivo roles played by DsbA and DsbC in the formation of protein disulfide bonds." Journal of Biological Chemistry 273, no. 42 (October 1998): 27756. http://dx.doi.org/10.1016/s0021-9258(19)59734-4.

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Journal articles on the topic 'DSBF'

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