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Gotowa bibliografia na temat „Outer membrane protein A (OmpA)”

Autor: Grafiati

Data publikacji: 6 września 2023

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Artykuły w czasopismach na temat "Outer membrane protein A (OmpA)"

Wexler, Hannah M., Elizabeth Tenorio i Lilian Pumbwe. "Characteristics of Bacteroides fragilis lacking the major outer membrane protein, OmpA". Microbiology 155, nr 8 (1.08.2009): 2694–706. http://dx.doi.org/10.1099/mic.0.025858-0.

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OmpA1 is the major outer membrane protein of the Gram-negative anaerobic pathogen Bacteroides fragilis. We identified three additional conserved ompA homologues (ompA2–ompA4) and three less homologous ompA-like genes (ompAs 5, 6 and 7) in B. fragilis. We constructed an ompA1 disruption mutant in B. fragilis 638R (WAL6 ΩompA1) using insertion-mediated mutagenesis. WAL6 ΩompA1 formed much smaller colonies and had smaller, rounder forms on Gram stain analysis than the parental strain or other unrelated disruption mutants. SDS-PAGE and Western blot analysis (with anti-OmpA1 IgY) of the OMP patterns of WAL6 ΩompA1 grown in both high- and low-salt media did not reveal any other OmpA proteins even under osmotic stress. An ompA1 deletant (WAL186ΔompA1) was constructed using a two-step double-crossover technique, and an ompA ‘reinsertant’, WAL360+ompA1, was constructed by reinserting the ompA gene into WAL186ΔompA1. WAL186ΔompA1 was significantly more sensitive to exposure to SDS, high salt and oxygen than the parental (WAL108) or reinsertant (WAL360+ompA1) strain. No significant change was seen in MICs of a variety of antimicrobials for either WAL6 ΩompA1 or WAL186ΔompA1 compared to WAL108. RT-PCR revealed that all of the ompA genes are transcribed in the parental strain and in the disruption mutant, but, as expected, ompA1 is not transcribed in WAL186ΔompA1. Unexpectedly, ompA4 is also not transcribed in WAL186ΔompA1. A predicted structure indicated that among the four OmpA homologues, the barrel portion is more conserved than the loops, except for specific conserved patches on loop 1 and loop 3. The presence of multiple copies of such similar genes in one organism would suggest a critical role for this protein in B. fragilis.

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Puig, Marta, Carme Fusté i Miquel Viñas. "Outer membrane proteins from Serratia marcescens". Canadian Journal of Microbiology 39, nr 1 (1.01.1993): 108–11. http://dx.doi.org/10.1139/m93-015.

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The outer membrane proteins (OMPs) of several strains of Serratia marcescens have been studied by sodium dodecyl sulphate – urea – polyacrylamide gel electrophoresis. Four major OMPs, named Omp1, Omp2, Omp3, and OmpA (42, 40, 39, and 37 kDa, respectively), have been visualized. The relative proportions of Omp2 and Omp3 depend on cultural conditions (temperature of incubation, osmolarity, and nutrient availability).Key words: Serratia marcescens, outer membrane proteins, porin.

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Roy Chowdhury, Atish, Shivjee Sah, Umesh Varshney i Dipshikha Chakravortty. "Salmonella Typhimurium outer membrane protein A (OmpA) renders protection from nitrosative stress of macrophages by maintaining the stability of bacterial outer membrane". PLOS Pathogens 18, nr 8 (15.08.2022): e1010708. http://dx.doi.org/10.1371/journal.ppat.1010708.

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Bacterial porins are highly conserved outer membrane proteins used in the selective transport of charged molecules across the membrane. In addition to their significant contributions to the pathogenesis of Gram-negative bacteria, their role(s) in salmonellosis remains elusive. In this study, we investigated the role of outer membrane protein A (OmpA), one of the major outer membrane porins of Salmonella, in the pathogenesis of Salmonella Typhimurium (STM). Our study revealed that OmpA plays an important role in the intracellular virulence of Salmonella. An ompA deficient strain of Salmonella (STM ΔompA) showed compromised proliferation in macrophages. We found that the SPI-2 encoded virulence factors such as sifA and ssaV are downregulated in STM ΔompA. The poor colocalization of STM ΔompA with LAMP-1 showed that disruption of SCV facilitated its release into the cytosol of macrophages, where it was assaulted by reactive nitrogen intermediates (RNI). The enhanced recruitment of nitrotyrosine on the cytosolic population of STM ΔompAΔsifA and ΔompAΔssaV compared to STM ΔsifA and ΔssaV showed an additional role of OmpA in protecting the bacteria from host nitrosative stress. Further, we showed that the generation of greater redox burst could be responsible for enhanced sensitivity of STM ΔompA to the nitrosative stress. The expression of several other outer membrane porins such as ompC, ompD, and ompF was upregulated in STM ΔompA. We found that in the absence of ompA, the enhanced expression of ompF increased the outer membrane porosity of Salmonella and made it susceptible to in vitro and in vivo nitrosative stress. Our study illustrates a novel mechanism for the strategic utilization of OmpA by Salmonella to protect itself from the nitrosative stress of macrophages.

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Hounsome, Jonathan D. A., Susan Baillie, Mojtaba Noofeli, Alan Riboldi-Tunnicliffe, Richard J. S. Burchmore, Neil W. Isaacs i Robert L. Davies. "Outer Membrane Protein A of Bovine and Ovine Isolates of Mannheimia haemolytica Is Surface Exposed and Contains Host Species-Specific Epitopes". Infection and Immunity 79, nr 11 (6.09.2011): 4332–41. http://dx.doi.org/10.1128/iai.05469-11.

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ABSTRACTMannheimia haemolyticais the etiological agent of pneumonic pasteurellosis of cattle and sheep; two different OmpA subclasses, OmpA1 and OmpA2, are associated with bovine and ovine isolates, respectively. These proteins differ at the distal ends of four external loops, are involved in adherence, and are likely to play important roles in host adaptation.M. haemolyticais surrounded by a polysaccharide capsule, and the degree of OmpA surface exposure is unknown. To investigate surface exposure and immune specificity of OmpA among bovine and ovineM. haemolyticaisolates, recombinant proteins representing the transmembrane domain of OmpA from a bovine serotype A1 isolate (rOmpA1) and an ovine serotype A2 isolate (rOmpA2) were overexpressed, purified, and used to generate anti-rOmpA1 and anti-rOmpA2 antibodies, respectively. Immunogold electron microscopy and immunofluorescence techniques demonstrated that OmpA1 and OmpA2 are surface exposed, and are not masked by the polysaccharide capsule, in a selection ofM. haemolyticaisolates of various serotypes and grown under different growth conditions. To explore epitope specificity, anti-rOmpA1 and anti-rOmpA2 antibodies were cross-absorbed with the heterologous isolate to remove cross-reacting antibodies. These cross-absorbed antibodies were highly specific and recognized only the OmpA protein of the homologous isolate in Western blot assays. A wider examination of the binding specificities of these antibodies forM. haemolyticaisolates representing different OmpA subclasses revealed that cross-absorbed anti-rOmpA1 antibodies recognized OmpA1-type proteins but not OmpA2-type proteins; conversely, cross-absorbed anti-rOmpA2 antibodies recognized OmpA2-type proteins but not OmpA1-type proteins. Our results demonstrate that OmpA1 and OmpA2 are surface exposed and could potentially bind to different receptors in cattle and sheep.

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Scott, Daniel C., Salete M. C. Newton i Phillip E. Klebba. "Surface Loop Motion in FepA". Journal of Bacteriology 184, nr 17 (1.09.2002): 4906–11. http://dx.doi.org/10.1128/jb.184.17.4906-4911.2002.

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ABSTRACT Using a lysine-specific cleavable cross-linking reagent ethylene glycolbis(sulfosuccimidylsuccinate) (Sulfo-EGS), we studied conformational motion in the surface loops of Escherichia coli FepA during its transport of the siderophore ferric enterobactin. Site-directed mutagenesis determined that Sulfo-EGS reacted with two lysines, K332 and K483, and at least two other unidentified Lys residues in the surface loops of the outer membrane protein. The reagent cross-linked K483 in FepA L7 to either K332 in L5, forming a product that we designated band 1, or to the major outer membrane proteins OmpF, OmpC, and OmpA, forming band 2. Ferric enterobactin binding to FepA did not prevent modification of K483 by Sulfo-EGS but blocked its cross-linking to OmpF/C and OmpA and reduced its coupling to K332. These data show that the loops of FepA undergo conformational changes in vivo, with an approximate magnitude of 15 Å, from a ligand-free open state to a ligand-bound closed state. The coupling of FepA L7 to OmpF, OmpC, or OmpA was TonB independent and was unaffected by the uncouplers CCCP (carbonyl cyanide m-chlorophenylhydrazone) and DNP (2,4-dinitrophenol) but completely inhibited by cyanide.

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Subramaniam, Sumathi, Bin Huang, Hilda Loh, Jimmy Kwang, Hai-Meng Tan, Kim-Lee Chua i Joachim Frey. "Characterization of a Predominant Immunogenic Outer Membrane Protein of Riemerella anatipestifer". Clinical Diagnostic Laboratory Immunology 7, nr 2 (1.03.2000): 168–74. http://dx.doi.org/10.1128/cdli.7.2.168-174.2000.

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ABSTRACT The ompA gene, encoding the 42-kDa major antigenic outer membrane protein OmpA of Riemerella anatipestifer, the etiololgical agent of septicemia anserum exsudativa, was cloned and expressed in Escherichia coli. Recombinant OmpA displayed a molecular mass similar to that predicted from the nucleotide sequence of the ompA gene but lower than that observed in total cell lysates of R. anatipestifer. The ompA gene showed a conserved C-terminal region comprising the OmpA-like domain and a variable N-terminal region. This structure is similar to those of the analogous outer membrane proteins of several gram-negative bacteria. However, OmpA of R. anatipestifercontains six EF-hand calcium-binding domains and two PEST regions, which distinguish it from other outer membrane proteins. The occurrence of these motifs in OmpA suggests a possible role in virulence for this protein. The ompA gene is present in the R. anatipestifer type strain and in all serotype reference strains. However, it exhibits some minor genetic heterogeneity among different serotypes, which seems not to affect the strong antigenic characteristics of the protein. OmpA is a conserved and strong antigenic determinant of R. anatipestifer and hence is suggested to be a valuable protein for the serodetection of R. anatipestifer infections, independent of their serotype.

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Charlson, Emily S., John N. Werner i Rajeev Misra. "Differential Effects of yfgL Mutation on Escherichia coli Outer Membrane Proteins and Lipopolysaccharide". Journal of Bacteriology 188, nr 20 (1.10.2006): 7186–94. http://dx.doi.org/10.1128/jb.00571-06.

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ABSTRACT YfgL together with NlpB, YfiO, and YaeT form a protein complex to facilitate the insertion of proteins into the outer membrane of Escherichia coli. Without YfgL, the levels of OmpA, OmpF, and LamB are significantly reduced, while OmpC levels are slightly reduced. In contrast, the level of TolC significantly increases in a yfgL mutant. When cells are depleted of YaeT or YfiO, levels of all outer membrane proteins examined, including OmpC and TolC, are severely reduced. Thus, while the assembly pathways of various nonlipoprotein outer membrane proteins may vary through the step involving YfgL, all assembly pathways in Escherichia coli converge at the step involving the YaeT/YfiO complex. The negative effect of yfgL mutation on outer membrane proteins may in part be due to elevated sigma E activity, which has been shown to downregulate the synthesis of various outer membrane proteins while upregulating the synthesis of periplasmic chaperones, foldases, and lipopolysaccharide. The data presented here suggest that the yfgL effect on outer membrane proteins also stems from a defective assembly apparatus, leading to aberrant outer membrane protein assembly, except for TolC, which assembles independent of YfgL. Consistent with this view, the simultaneous absence of YfgL and the major periplasmic protease DegP confers a synthetic lethal phenotype, presumably due to the toxic accumulation of unfolded outer membrane proteins. The results support the hypothesis that TolC and major outer membrane proteins compete for the YaeT/YfiO complex, since mutations that adversely affect synthesis or assembly of major outer membrane proteins lead to elevated TolC levels.

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Oh, Kyu-Wan, Kyeongmin Kim, Md Maidul Islam, Hye-Won Jung, Daejin Lim, Je Chul Lee i Minsang Shin. "Transcriptional Regulation of the Outer Membrane Protein A in Acinetobacter baumannii". Microorganisms 8, nr 5 (11.05.2020): 706. http://dx.doi.org/10.3390/microorganisms8050706.

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Acinetobacter baumannii is known for its virulence in severely ill, hospitalized patients and for exhibiting multidrug resistance. A. baumannii infection treatment poses a serious problem in clinical environments. The outer membrane protein A (OmpA) of the Acinetobacter genus is involved in bacterial virulence. Regulatory factors of OmpA in the post-transcriptional stage have been previously identified. However, the regulatory factors that act before the transcriptional stage remain unclear. We investigated the A1S_0316 gene that encodes a putative transcription factor for OmpA expression in A. baumannii. A1S_0316 was purified and examined using size-exclusion chromatography, which revealed that it forms an oligomer. The binding affinity of A1S_0316 to the OmpA promoter region was also examined. We compared the binding affinity to the OmpA promotor region between A1S_0316 and the AbH-NS protein. A1S_0316 showed higher binding affinity to the OmpA promotor region than did H-NS. We examined the regulatory effect of these proteins on OmpA expression in A. baumannii using real-time qPCR and various in vitro tools. Our results indicated that A1S_0316 acts as an anti-repressor on the promotor region of the OmpA gene by inhibiting the binding of the AbH-NS protein. This study was the first demonstration of the transcriptional regulation of OmpA expression.

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Pai, Suresh R., Yvonne Upshaw i Shiva P. Singh. "Characterization of monoclonal antibodies to the outer membrane protein (OmpD) of Salmonella typhimurium". Canadian Journal of Microbiology 38, nr 11 (1.11.1992): 1102–7. http://dx.doi.org/10.1139/m92-181.

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A panel of monoclonal antibodies, seven against the trimeric and seven against the monomeric forms to outer membrane protein D (OmpD) of Salmonella typhimurium were produced. The specificities of these monoclonal antibodies for the porin proteins of S. typhimurium and their cross-reactions with Salmonella porins OmpC and OmpF were determined by Western immunoblotting and enzyme-linked immunosorbent assay. We observed that OmpD shared more epitopes and had greater structural similarity with OmpC than with OmpF. Key words: Salmonella typhimurium, outer membrane protein, monoclonal antibody, trimeric, monomeric.

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Singh, Pushpendra, Manish Kumar Tripathi, Mohammad Yasir, Ashish Ranjan i Rahul Shrivastava. "Effects of carbamate pesticides intermediates on Escherichia coli membrane architecture: An in vitro and in silico approach". Environmental Analysis Health and Toxicology 36, nr 3 (25.08.2021): e2021020. http://dx.doi.org/10.5620/eaht.2021020.

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Methyl isocyanate (MIC), a low molecular weight synthetic aliphatic compound, having an isocyanate group (−NCO), has industrial application. In this study, the effects of methyl isocyanate and its mechanism on outer membrane protein of Escherichia coli were observed using experimental and computational methods. In vitro exposure of N-succinimidyl N-methylcarbamate (NSNM) a synthetic analogue of MIC on E. coli to a final concentration of 2 mM was found to affect the growth curve pattern and changes in cell morphology. Molecular docking studies of MIC and NSNM with E. coli outer membrane protein (OmpW, OmpX, OmpF OmpA), and periplasmic domain (PAL) were performed. The in-silico results revealed that outer membrane protein OmpF showed the highest negative binding energy, i.e. ∆G -4.11 kcal/mole and ∆G -3.19 kcal/mole by NSNM and MIC as compared to other proteins. Our study concludes that methyl isocyanate retains lethal toxicity which leads to cell death due to the membrane protein damage of E. coli membrane.

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Rozprawy doktorskie na temat "Outer membrane protein A (OmpA)"

Kaye, Elena Cortizas. "The Function of Outer Membrane Protein A (OmpA) in Yersinia pestis". Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_theses/58.

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The outer membrane protein OmpA is one of the major outer membrane proteins in many species of bacteria, including the Yersiniae. Our goal was to explore the role of OmpA in Y. pestis. This encompasses the ability of Yersinia to infect and survive within macrophages, as well as to resist antimicrobial compounds. Our laboratory found that a delta ompA mutant is impaired in a macrophage-associated infectivity assay. We also found that OmpA might play a role in the ability of the bacteria to resist antimicrobial peptides, specifically polymyxin B. Aditionally, we assessed the differences in OmpA of Y. pestis and E. coli, and determined that the characteristics we have observed in Y. pestis are unique compared to what has previously been described in E. coli. Our results indicate that Y. pestis OmpA might act through known pathways of antimicrobial resistance such as the PhoPQ two-component regulatory system, although further experiments are needed to determine the precise mechanism of function OmpA. Overall, our project characterizes the different functions of OmpA in Y. pestis, both as a key player in intracellular survival and as a necessary component in conferring resistance to antimicrobial peptides.

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Schesser, Bartra Sara Celinda. "Outer membrane proteins of Yersinia pestis : Ail and OmpA". Doctoral thesis, Umeå universitet, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-33956.

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A vast number of studies have been completed on the virulence determinants of Yersinia spp.; however, the focus of many of these studies has been on the virulence plasmid and the plasmid-encoded Type three secretion system. Nevertheless, many chromosomal genes whose products are directly involved in virulence have also been identified. Some of these critical virulence determinants are outer membrane proteins. Outer membrane proteins of Gram-negative bacteria often have important physiological roles; however, some have also been found to be important for pathogenesis. In this thesis, we investigated two Yersinia. pestis outer membrane proteins, Ail and OmpA, and their roles in virulence. We provide evidence that Y. pestis Ail is a highly expressed outer membrane protein that is absolutely essential for Y. pestis to resist the killing action of the complement system present in human blood and tissues, as well as the blood and tissues of other mammalian hosts. Furthermore, Ail was important for virulence in a Y. pestis-Canorhabditis elegans model of infection.The work in this thesis also provided the first evidence that another surface-exposed outer membrane protein, termed OmpA, is required for both Yersinia pseudotuberculosis and Y. pestis to survive and proliferate intracellularly in macrophages. Finally, we provide evidence that Y. pestis has a functional small RNA MicA that controls the expression of OmpA. This is the first demonstration of sRNA-mediated regulation of a Yersinia virulence factor. This work has paved the way for future studies on the role of outer membrane proteins in virulence, particularly the role of Ail and OmpA.

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Al-Akash, Ahmed M. "Increased expression of ompA, ompX, dedA, and gutS genes in Enterobacter sp. YSU in the presence of selenite". Youngstown State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1607517925584702.

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McCallan, Lyanne Mary. "Differentiation of Campylobacter jejuni on the basis of outer membrane protein (OMP) patterns". Thesis, University of Ulster, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422191.

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Gerlach, Lisa [Verfasser]. "BamB facilitates folding of outer membrane protein A (OmpA) via interactions of its β-propeller with the membrane surface and via a conformation change induced by phosphatidylglycerol / Lisa Gerlach". Kassel : Universitätsbibliothek Kassel, 2020. http://d-nb.info/1204016488/34.

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Kevin, Gross. "Characterization of a fourU RNA thermometer in the ompA gene of Shigella dysenteriae". Ohio University Honors Tutorial College / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1367582905.

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Dahlstrand, Rudin Arvid, i John Burstedt. "The importance of OuterMembrane Protein A in SerumResistance in Aggregatibacteractinomycetemcomitans serotype astrain D7SS". Thesis, Umeå universitet, Institutionen för odontologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-143904.

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The Gram-negative bacterium Aggregatibacter actinomycetemcomitans is primarily associatedwith aggressive forms of periodontal disease. Additionally, it has occasionally been found to causemetastatic infections in non-oral sites. This requires the ability to evade the bactericidal activity ofthe complement system of the humoral immune system. Outer membrane proteins, namely,Omp100 and OmpA have been connected to normal human serum resistance for several bacteriaspecies. The objective of this study was to investigate if serum-resistant ompA mutants can beobtained, and to detect changes in OMP expression. We used A. actinomycetemcomitansserotype a strain D7SS and D7SS ompA knockouts. The strains were incubated in 50 % NHS.This resulted in a substantial decrease of survival among D7SS ompA knockouts. D7SS ompAknockouts were exposed to 50 % NHS once more to confirm stable serum resistance. 13 out of14 tested clones showed growth, indicating that serum resistant ompA mutants could begenerated. SDS-PAGE gel of extracted outer membrane vesicles revealed an additional proteinband of approximately 34 kDa in at least 4 of 5 tested serum resistant ompA mutants. This proteinband has been analyzed in the laboratory, and according to LC-MS/MS it contains an OmpAhomologue, which has been named OmpA2. We conclude that OmpA2 expression might be amajor mechanism for serum survival in A. actinomycetemcomitans serotype a strain D7SS ompAknockouts.

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Easton, Donna Meredith, i n/a. "Functional and Antigenic Characterisation of the Moraxella catarrhalis protein M35". University of Canberra. n/a, 2008. http://erl.canberra.edu.au./public/adt-AUC20081217.083105.

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This thesis reports the characterisation of a novel outer membrane protein (OMP) from M. catarrhalis, designated M35, with a molecular mass of 36.1 kDa. This protein is structurally homologous to classic Gram-negative porins, such as OMP C from E. coli and OMP K36 from K. pneumoniae, with a predicted structure of 8 surface loops connecting 16 antiparallel -sheets. Comparison of the DNA sequences of the M35 genes from 18 diverse clinical isolates showed that the gene was highly conserved (99.6-100 % of nucleotides) with only one isolate (ID78LN266) having base variations that resulted in amino acid substitutions. A single amino acid mutation in the 3rd external loop of M35 in isolate ID78LN266 significantly affected antibody recognition, indicating that loop 3 contains an immunodominant B-cell epitope. The reduction in antibody-binding to M35 from ID78LN266 was similar to that caused by complete removal of loop 3. Since loop 3 folds into the porin channel in the classic structure, the antibody specificity to loop 3 was hypothesised to be a potential mechanism for evasion of host immune responses targeted to M35, potentially explaining the high degree of conservation across isolates. A series of recombinant proteins were constructed to analyse the binding to M35 of antibodies specificity for loop 3 or the remainder of the protein. It was found that loop 3- specific antibodies were not able to bind to M35 on the surface of M. catarrhalis and that this corresponds both with a lack of ability to enhance opsonophagocytosis in vitro and bacterial clearance in vivo. Additionally, antibodies raised against a version of M35 lacking loop 3 and M35 from the variant isolate ID78LN266 were both no less effective than the full consensus M35 by both these measures. It therefore appears that while the majority of antibodies raised against M35 are specific for loop 3 these antibodies do not mediate anti-M. catarrhalis actions. Two deletion mutant strains of M. catarrhalis that do not contain the outer membrane protein M35 were created by insertional inactivation of the M35 gene. Growth comparisons between these mutant strains and their wildtype parent strains initially led to the hypothesis that M35 is necessary for efficient glutamic acid uptake by M. catarrhalis, however this hypothesis was later shown to be incorrect. Efficient uptake of glutamic acid seemed to be mediated by a novel 40 kDa protein that was up-regulated in the deletion mutant strains, presumably to compensate for the lack of M35. M35 was also found to be essential for in vivo survival of M. catarrhalis in the nasal cavities of mice, indicating that it is an essential functional protein for colonisation of the mucosal surface.

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Li, Huanyu. "Structural studies of the BAM complex, OmpU outer membrane protein and lipoprotein N-acyl transferase in Gram-negative bacteria". Thesis, University of East Anglia, 2017. https://ueaeprints.uea.ac.uk/68718/.

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Structural studies of membrane proteins represent a significant challenge in the field owing to their hydrophobic nature, unstable property and resistance to be crystallized. In Gramnegative bacteria, membrane proteins contribute to the characteristic membranous architecture composed of an asymmetric layer of outer membrane (OM) and a symmetric inner cytoplasmic membrane (IM). Outer membrane proteins (OMPs) play essential roles in nutrient uptake, protein transport, outer membrane assembly, and pathogenesis of Gram-negative bacteria. In Escherichia coli, nearly all the outer membrane proteins are inserted into the outer membrane by the β-barrel assembly machinery (BAM), which contains one conserved membrane protein BamA and four lipoproteins BamBCDE. The individual protein structures of the BAM complex have been reported, but the mechanism of OMP assembly by the BAM complex is halted by a lack of structure of the whole complex. During the course of the collaborative BAM complex project, I participated in structural studies of the BAM complex and generated high resolution crystallographic diffraction data that contributes to one of the two determined structures of the BAM complex, and the structural insights have enlightened understanding of the in vivo insertion mechanism. Of diverse types of β-barrel OMPs that are inserted into the OM by the BAM complex, an outer membrane protein called OmpU from Vibrio cholerae is a potential virulence factor in addition to its porin identity with undefined atomic structure. I determined the crystal structure of this OMP, in which the long and flexible extracellular loop L4 and a novel Nterminal coil in the pore lumen provide direct structural evidence underlying its particular functions. The symmetric lipid bilayer of IM accommodates an even more diverse array of IMPs composed of the contrasting dominance of α-helices. Three IMPs are responsible for conducting post-translational modifications of lipoproteins in Gram-negative bacteria, a class of proteins destined to reside on the periplasmic side of either the IM or the OM via acyl chains post-translationally linked to the N-terminal cysteine residues, and they are called phosphatidylglycerol:prolipoprotein diacylglyceryl transferase (Lgt), Prolipoprotein signal peptidase (Lsp) and apolipoprotein N-acyltransferase (Lnt). Structural studies were carried out on Lnt but unsuccessful in determining the atomic structure. Recent structures of Lnt reported during the course of this project are consistent with earlier biochemical studies that piloted the understanding of its function and further elucidate the molecular mechanisms of its primary acyl-transfer function.

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Holmqvist, Erik. "Macromolecular Matchmaking : Mechanisms and Biology of Bacterial Small RNAs". Doctoral thesis, Uppsala universitet, Mikrobiologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-171642.

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Cells sense the properties of the surrounding environment and convert this information into changes in gene expression. Bacteria are, in contrast to many multi-cellular eukaryotes, remarkable in their ability to cope with rapid environmental changes and to endure harsh and extreme milieus. Previously, control of gene expression was thought to be carried out exclusively by proteins. However, it is now clear that small regulatory RNAs (sRNA) also carry out gene regulatory functions. Bacteria such as E. coli harbor a large class of sRNAs that bind to mRNAs to alter translation and/or mRNA stability. By identifying mRNAs that are targeted by sRNAs, my studies have broadened the understanding of the mechanisms that underlie sRNA-dependent gene regulation, and have shed light on the impact that this type of regulation has on bacterial physiology. Control of gene expression often relies on the interplay of many regulators. This interplay is exemplified by our discovery of mutual regulation between the sRNA MicF and the globally acting transcription factor Lrp. Through double negative feedback, these two regulators respond to nutrient availability in the environment which results in reprogramming of downstream gene expression. We have also shown that both the transcription factor CsgD, and the anti-sigma factor FlgM, are repressed by the two sRNAs OmrA and OmrB, suggesting that these sRNAs are important players in the complex regulation that allow bacteria to switch between motility and sessility. Bacterial populations of genetically identical individuals show phenotypic variations when switching to the sessile state due to bistability in gene expression. While bistability has previously been demonstrated to arise from stochastic fluctuations in transcription, our results suggest that bistability possibly may arise from sRNA-dependent regulatory events also on the post-transcriptional level.

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Książki na temat "Outer membrane protein A (OmpA)"

Shand, Geoffrey Harold. Antibiotic resistance and outer membrane protein antigens of Pseudomonas aeruginasa. Birmingham: University of Aston. Department of Pharmaceutical Sciences, 1985.

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Kraak, Wilma A. G. Outer membrane protein typing of Haemophilus influenzae: An epidemiological tool in type b and non-encapsulated strains. Oxford: Oxford Polytechnic, 1990.

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Kania, Stephen Anthony. Isolation and characterization of a 78,000 dalton outer membrane protein of Haemophilus somnus. 1987.

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The 2.05 Å crystal structure of LptB, an essential protein in gram-negative bacterial outer membrane biogenesis. 2011.

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Structural and Functional Relationships in Prokaryotes. Springer, 2004.

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Barton, Larry L. Structural and Functional Relationships in Prokaryotes. Springer London, Limited, 2005.

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Części książek na temat "Outer membrane protein A (OmpA)"

Fahie, Monifa A. V., Bib Yang, Christina M. Chisholm i Min Chen. "Protein Analyte Sensing with an Outer Membrane Protein G (OmpG) Nanopore". W Methods in Molecular Biology, 77–94. New York, NY: Springer US, 2020. http://dx.doi.org/10.1007/978-1-0716-0806-7_7.

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Sugawara, Etsuko, i Hiroshi Nikaido. "OmpA/OprF: Slow Porins or Channels Produced by Alternative Folding of Outer Membrane Proteins". W Bacterial and Eukaryotic Porins, 119–38. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2005. http://dx.doi.org/10.1002/3527603875.ch7.

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Yung-Hung, Roy Lee, Theam Soon Lim, Asma Ismail i Yee Siew Choong. "The Molecular Dynamics Simulation of a Multi-domain Outer Membrane Protein A (OmpA) from Shigella flexneri in POPE Lipid Bilayer". W Chemistry for a Clean and Healthy Planet, 71–83. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-20283-5_4.

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Corbett, M. J., J. R. Black i C. E. Wilde. "Antibodies to outer membrane protein — macromolecular complex (OMP-MC) are bactericidal for serum-resistant gonococci". W Gonococci and Meningococci, 685–91. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-1383-7_107.

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Ganguly, Bhaskar. "Computational Prediction of Immunodominant Epitopes on Outer Membrane Protein (Omp) H of Pasteurella multocida Toward Designing of a Peptide Vaccine". W Vaccine Design, 51–57. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3389-1_3.

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Poolman, J. "Outer Membrane Protein Vaccines". W Vaccines, 225–48. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-59955-2_9.

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Nanda, Vikas, Daniel Hsieh i Alexander Davis. "Prediction and Design of Outer Membrane Protein–Protein Interactions". W Membrane Proteins, 183–96. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-583-5_10.

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Poolman, Jan T. "Bacterial Outer Membrane Protein Vaccines". W Advances in Experimental Medicine and Biology, 73–77. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4899-1382-1_11.

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Tommassen, Jan, i Romé Voulhoux. "Biogenesis of Outer Membrane Proteins". W Protein Secretion Pathways in Bacteria, 83–97. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-010-0095-6_5.

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Cecil, Jessica D., Natalie Sirisaengtaksin, NEIL M. O'BRIEN-SIMPSON i Anne Marie Krachler. "Outer Membrane Vesicle-Host Cell Interactions". W Protein Secretion in Bacteria, 201–14. Washington, DC, USA: ASM Press, 2019. http://dx.doi.org/10.1128/9781683670285.ch17.

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Streszczenia konferencji na temat "Outer membrane protein A (OmpA)"

Handayani, Tri, Dadang Priyoatmojo i Afi Candra Trinugraha. "Outer Membrane Protein (OMP) Profiles of Brucella abortus Local Isolate by SDS-PAGE Procedure". W International Conference on Improving Tropical Animal Production for Food Security (ITAPS 2021). Paris, France: Atlantis Press, 2022. http://dx.doi.org/10.2991/absr.k.220309.006.

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Fontes, Silvia, Thais Araujo, Fernando Conte, Patrícia Neves, Rodrigo Silva, Tatiana Rozental i Elba Lemos. "In silico studies of Coxiella burnetii outer membrane proteins (OMPs) as basis to Q fever diagnosis development". W IV International Symposium on Immunobiologicals & VII Seminário Anual Científico e Tecnológico. Instituto de Tecnologia em Imunobiológicos, 2019. http://dx.doi.org/10.35259/isi.sact.2019_32727.

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Pires, Inês, i Miguel Machuqueiro. "pH-dependent permeability of outer membrane protein G: an in silico study". W MOL2NET 2018, International Conference on Multidisciplinary Sciences, 4th edition. Basel, Switzerland: MDPI, 2018. http://dx.doi.org/10.3390/mol2net-04-06077.

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Harasztosi, Csaba, Emese Harasztosi i Anthony W. Gummer. "Membrane recycling at the infranuclear pole of the outer hair cell". W MECHANICS OF HEARING: PROTEIN TO PERCEPTION: Proceedings of the 12th International Workshop on the Mechanics of Hearing. AIP Publishing LLC, 2015. http://dx.doi.org/10.1063/1.4939332.

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Voigt, W., W. Rabsch i H. Tschäpe. "Differences in the outer membrane protein pattern of Salmonella typhimurium DT8, DT10 and DT104 strains". W Fourth International Symposium on the Epidemiology and Control of Salmonella and Other Food Borne Pathogens in Pork. Iowa State University, Digital Press, 2001. http://dx.doi.org/10.31274/safepork-180809-201.

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Shen, Dandan, Anchun Cheng i Mingshu Wang. "Analysis of synonymous codon usage in the outer membrane efflux protein gene of Riemerella anatipestifer". W 2012 5th International Conference on Biomedical Engineering and Informatics (BMEI). IEEE, 2012. http://dx.doi.org/10.1109/bmei.2012.6513098.

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Wilkinson, J. M., N. Hack, L. I. Thorsen i J. A. Thomas. "MONOCLONAL ANTIBODIES RECOGNISING PROTEINS OF THE OUTER AND INNER SURFACE OF THE PLATELET PLASMA MEMBRANE". W XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644493.

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Platelet membrane preparations can be fractionated into two major subpopulations by free flow electrophoresis and these have been shown to correspond to the plasma membrane and the endoplasmic reticulum of the platelet. The plasma membrane fraction can be shown, by two-dimensional electrophoresis, to contain the major surface glycoproteins together with considerable amounts of actin and actin-associated proteins such as the 250 kDa actin-binding protein (filamin), P235 (talin), myosin, α-actinin and tropomyosin (Hack, N. … Crawford, N., Biochem. J. 222, 235 (1984). These cytoskeletal proteins are associated with the cytoplasmic face of the plasma membrane and probably interact with transmembrane glycoproteins. We have raised monoclonal antibodies to the purified plasma membrane preparation in order to investigate the nature of these glycoprotein-cytoskeletal interactions. In two fusion experiments, out of 804 tested, 104 hybrids secreted antibody to the membrane preparation and of these 24 were selected for further study. Initial assays were by ELISA using either the membrane preparation or whole fixed platelets as the target antigen. The specificity of the antibodies was investigated further by immunoblotting of SDS gels of total platelet proteins prepared under reducing and nonreducing conditions, by immunofluorescence, by immunohisto-chemistry and by crossed immunoelectrophoresis. The majority of the antibodies recognise major surface glycoproteins; of these, four bind to glycoprotein Ib under all conditions examined while another seven recognise the glycoprotein IIb/IIIa complex as detected by crossed immunoelectrophoresis. Three antibodies recognise the actin binding protein and these cross-react with the smooth muscle protein filamin in a number of different species. Further characterisation of these antibodies in both structural and functional terms will be presented.We are grateful to the Smith and Nephew Foundation for financial support for these studies

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Salamon, Zdzislaw, Gordon Tollin, Angus Macleod i Ian C. Stevenson. "Spectroscopic studies of membrane protein-lipid bilayer systems deposited on multilayer thin film coatings". W Optical Interference Coatings. Washington, D.C.: Optica Publishing Group, 1997. http://dx.doi.org/10.1364/oic.1998.thd.1.

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Although thin film coatings have been used for many years in optical investigations of biological systems (especially as narrow band light filters), more recent applications of such films in two types of spectroscopic devices, surface plasmon resonance (SPR) and optical waveguides, have provided new biophysical tools for the study of protein-protein and protein-lipid membrane interactions [1]. Although both of these techniques are based on different physical phenomena, the thin film coatings have the same function, i.e. coupling devices in which incident light, under the appropriate optical conditions, can generate an evanescent surface-bound electromagnetic field, which propagates along the interface between the thin film and the emergent dielectric medium in a manner which depends on the interface characteristics. The resulting electric field intensity is concentrated at the outer surface of the film, and diminishes exponentially on both sides of the interface. As a consequence of these properties, it is possible to use SPR and waveguide spectroscopy to probe a few nanometers from the coated surface, a distance well below the wavelength of the light used to generate the evanescent waves, and hence these phenomena have been utilized extensively in studies of surfaces and thin films [for references see 1,2]. Although numerous other optical techniques have also been applied to such systems (e.g. ellipsometry, interferometry, spectrophotometry, and various forms of microscopy), the SPR method has very recently regained its popularity, mainly because of its superior sensitivity, as well as some additional very important advantages over these other methodologies [1,2]. These latter advantages include the following. First, the complete system of measurement is located on the side of the apparatus which is remote from the sample, and thus there is no optical interference from the bulk medium. Second, the outer surface of the sample needs no treatment to increase reflectance, because the necessary high reflectivity is achieved by using total internal reflectance. Third, there are three principal parameters of the resonance that can readily be measured, thereby yielding much more information about the sample and changes within it than the simple interferometric step height used in other sensitive optical techniques.

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McBride, S., M. Ferguson, M. Kelly, K. Hawley, A. Luthra, H. Driscoll, J. Montezuma-Rusca i in. "P401 Development and Utilization of Antibodies Specific for Extracellular Loops of the Treponema pallidum outer membrane protein BamA (TP0326)". W Abstracts for the STI & HIV World Congress, July 14–17 2021. BMJ Publishing Group Ltd, 2021. http://dx.doi.org/10.1136/sextrans-2021-sti.431.

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"Evaluation of 36 KDa Outer Membrane Protein (OMP’s) by Latex Dri-dot of Salmonella Enterica Serovar Typhi For The Diagnosis Of Typhoid Fever". W April 17-18, 2018 Kyoto (Japan). International Institute of Chemical, Biological and Environmental Engineering, 2018. http://dx.doi.org/10.17758/iicbe1.c0418154.

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Raporty organizacyjne na temat "Outer membrane protein A (OmpA)"

Walian, P. J. Electron crystallography of PhoE porin, an outer membrane, channel- forming protein from E. coli. Office of Scientific and Technical Information (OSTI), listopad 1989. http://dx.doi.org/10.2172/6365889.

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Palmer, Guy H., Eugene Pipano, Terry F. McElwain, Varda Shkap i Donald P. Knowles, Jr. Development of a Multivalent ISCOM Vaccine against Anaplasmosis. United States Department of Agriculture, lipiec 1993. http://dx.doi.org/10.32747/1993.7568763.bard.

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Anaplasmosis is an arthropod+borne disease of cattle caused by the rickettsia Anaplasma marginale and an impediment to efficient production of healthy livestock in both Israel and the United States. Our research focuses on development of a recombinant membrane surface protein (MSP) immunogen to replace current vaccines derived from the blood of infected cattle. The risk of widespread transmission of both known and newly emergent pathogens has prevented licensure of live blood-based vaccines in the U.S. and is a major concern for their continued use in Israel. Briefly, we accomplished the following in our BARD supported research: i) characterization of the intramolecular and intermolecular relationships of the native Major Surface Proteins (MSP) in the outer membrane; ii) expression, purification, and epitope characterization of the recombinant MSP-2, MSP-3, MSP-4, and MSP-5 proteins required to construct the recombinant ISCOM; iii) demonstration that the outer membrane-Quil A induces CD4+ T lymphocytes specific for the outer membrane polypeptides; iv) identification of CD4+ T lymphocytes that recognize outer membrane polypeptide epitopes conserved among other wise antigenically distinct strains; v) determination that immunization with the outer membrane-Quil A construct does not affect the ability of ticks to acquire or transmit A. marginale; and vi) demonstration that the outer membrane-Quil A construct induces complete protection against rickettsemia upon homologous challenge and significant protection against challenge with antigenically distinct strains, including tick transmission. Importantly, the level of protection against homologous challenge in the MSP vaccinates was comparable to that induced by live blood-based vaccines and demonstrates that development of a new generation of vaccines is feasible.

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Elbaum, Michael, i Peter J. Christie. Type IV Secretion System of Agrobacterium tumefaciens: Components and Structures. United States Department of Agriculture, marzec 2013. http://dx.doi.org/10.32747/2013.7699848.bard.

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Objectives: The overall goal of the project was to build an ultrastructural model of the Agrobacterium tumefaciens type IV secretion system (T4SS) based on electron microscopy, genetics, and immunolocalization of its components. There were four original aims: Aim 1: Define the contributions of contact-dependent and -independent plant signals to formation of novel morphological changes at the A. tumefaciens polar membrane. Aim 2: Genetic basis for morphological changes at the A. tumefaciens polar membrane. Aim 3: Immuno-localization of VirB proteins Aim 4: Structural definition of the substrate translocation route. There were no major revisions to the aims, and the work focused on the above questions. Background: Agrobacterium presents a unique example of inter-kingdom gene transfer. The process involves cell to cell transfer of both protein and DNA substrates via a contact-dependent mechanism akin to bacterial conjugation. Transfer is mediated by a T4SS. Intensive study of the Agrobacterium T4SS has made it an archetypal model for the genetics and biochemistry. The channel is assembled from eleven protein components encoded on the B operon in the virulence region of the tumor-inducing plasmid, plus an additional coupling protein, VirD4. During the course of our project two structural studies were published presenting X-ray crystallography and three-dimensional reconstruction from electron microscopy of a core complex of the channel assembled in vitro from homologous proteins of E. coli, representing VirB7, VirB9, and VirB10. Another study was published claiming that the secretion channels in Agrobacterium appear on helical arrays around the membrane perimeter and along the entire length of the bacterium. Helical arrangements in bacterial membranes have since fallen from favor however, and that finding was partially retracted in a second publication. Overall, the localization of the T4SS within the bacterial membranes remains enigmatic in the literature, and we believe that our results from this project make a significant advance. Summary of achievements : We found that polar inflations and other membrane disturbances relate to the activation conditions rather than to virulence protein expression. Activation requires low pH and nutrient-poor medium. These stress conditions are also reflected in DNA condensation to varying degrees. Nonetheless, they must be considered in modeling the T4SS as they represent the relevant conditions for its expression and activity. We identified the T4SS core component VirB7 at native expression levels using state of the art super-resolution light microscopy. This marker of the secretion system was found almost exclusively at the cell poles, and typically one pole. Immuno-electron microscopy identified the protein at the inner membrane, rather than at bridges across the inner and outer membranes. This suggests a rare or transient assembly of the secretion-competent channel, or alternatively a two-step secretion involving an intermediate step in the periplasmic space. We followed the expression of the major secreted effector, VirE2. This is a single-stranded DNA binding protein that forms a capsid around the transferred oligonucleotide, adapting the bacterial conjugation to the eukaryotic host. We found that over-expressed VirE2 forms filamentous complexes in the bacterial cytoplasm that could be observed both by conventional fluorescence microscopy and by correlative electron cryo-tomography. Using a non-retentive mutant we observed secretion of VirE2 from bacterial poles. We labeled the secreted substrates in vivo in order detect their secretion and appearance in the plant cells. However the low transfer efficiency and significant background signal have so far hampered this approach.

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Brayton, Kelly A., Varda Shkap, Guy H. Palmer, Wendy C. Brown i Thea Molad. Control of Bovine Anaplasmosis: Protective Capacity of the MSP2 Allelic Repertoire. United States Department of Agriculture, styczeń 2014. http://dx.doi.org/10.32747/2014.7699838.bard.

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Anaplasmosis is an arthropod-borne disease of cattle caused by the rickettsia Anaplasmamarginale and is an impediment to efficient production of healthy livestock in both Israel and the United States. Currently, the only effective vaccines are derived from the blood of infected cattle. The risk of widespread transmission of both known and newly emergent pathogens has prevented licensure of live blood-based vaccines in the U.S. and is a major concern for their continued use in Israel. Consequently, development of a safe, effective vaccine is a high priority. Despite its drawbacks as a live, blood-based vaccine, the Israel vaccine strain protects against disease upon challenge with wild-type A. marginale in extensive experimental trials and during 50 years of deployment in Israel. Field studies in Australia and Argentina indicate that this protection is broadly effective. Thus, to identify antigens for development of a safe and effective recombinant vaccine, we have used a comparative genomics approach by sequencing the Israel vaccine strain and searching for shared surface antigens with sequenced wild-type U.S. strains. We have focused on Msp2, the immune-dominant but antigenically variable surface protein, based on shared structure among strains and demonstration that antibody from cattle immunized with the Israel vaccine strain binds Msp2 from the genetically and geographically distinct U.S. St. Maries strain, consistent with the ability to protect against St. Maries challenge. Importantly, we have defined the full repertoire of Msp2 simple variants encoded by the vaccine strain and hypothesize that a recombinant vaccine encoding this full repertoire will induce protection equivalent to that induced by the live vaccine strain. Any escape from immunity by generation of complex Msp2 variants is predicted to carry a severe fitness cost that prevents high-level bacteremia and disease— consistent with the type of protection induced by the live vaccine strain. We tested the hypothesis that the Msp2 simple variant repertoires in wild-type A. marginale strains are recognized by antibody from cattle immunized with the Israel vaccine strain and that immunization with the vaccine strain Msp2 repertoire can recapitulate the protection provided by the vaccine strain upon challenge with Israel and U.S. strains of A. marginale. Our findings demonstrate that a set of conserved outer membrane proteins are recognized by immune serum from A. centrale vaccinated animals but that this set of proteins does not include Msp2. These findings suggest that “subdominant” immunogens are required for vaccine induced protection.

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Splitter, Gary, i Menachem Banai. Microarray Analysis of Brucella melitensis Pathogenesis. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7709884.bard.

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Original Objectives 1. To determine the Brucella genes that lead to chronic macrophage infection. 2. To identify Brucella genes that contribute to infection. 3. To confirm the importance of Brucella genes in macrophages and placental cells by mutational analysis. Background Brucella spp. is a Gram-negative facultative intracellular bacterium that infects ruminants causing abortion or birth of severely debilitated animals. Brucellosis continues in Israel, caused by B. melitensis despite an intensive eradication campaign. Problems with the Rev1 vaccine emphasize the need for a greater understanding of Brucella pathogenesis that could improve vaccine designs. Virulent Brucella has developed a successful strategy for survival in its host and transmission to other hosts. To invade the host, virulent Brucella establishes an intracellular niche within macrophages avoiding macrophage killing, ensuring its long-term survival. Then, to exit the host, Brucella uses placenta where it replicates to high numbers resulting in abortion. Also, Brucella traffics to the mammary gland where it is secreted in milk. Missing from our understanding of brucellosis is the surprisingly lillie basic information detailing the mechanisms that permit bacterial persistence in infected macrophages (chronic infection) and dissemination to other animals from infected placental cells and milk (acute infection). Microarray analysis is a powerful approach to determine global gene expression in bacteria. The close genomic similarities of Brucella species and our recent comparative genomic studies of Brucella species using our B. melitensis microarray, suqqests that the data obtained from studying B. melitensis 16M would enable understanding the pathogenicity of other Brucella organisms, particularly the diverse B. melitensis variants that confound Brucella eradication in Israel. Conclusions Results from our BARD studies have identified previously unknown mechanisms of Brucella melitensis pathogenesis- i.e., response to blue light, quorum sensing, second messenger signaling by cyclic di-GMP, the importance of genomic island 2 for lipopolysaccharide in the outer bacterial membrane, and the role of a TIR domain containing protein that mimics a host intracellular signaling molecule. Each one of these pathogenic mechanisms offers major steps in our understanding of Brucella pathogenesis. Strikingly, our molecular results have correlated well to the pathognomonic profile of the disease. We have shown that infected cattle do not elicit antibodies to the organisms at the onset of infection, in correlation to the stealth pathogenesis shown by a molecular approach. Moreover, our field studies have shown that Brucella exploit this time frame to transmit in nature by synchronizing their life cycle to the gestation cycle of their host succumbing to abortion in the last trimester of pregnancy that spreads massive numbers of organisms in the environment. Knowing the bacterial mechanisms that contribute to the virulence of Brucella in its host has initiated the agricultural opportunities for developing new vaccines and diagnostic assays as well as improving control and eradication campaigns based on herd management and linking diagnosis to the pregnancy status of the animals. Scientific and Agricultural Implications Our BARD funded studies have revealed important Brucella virulence mechanisms of pathogenesis. Our publication in Science has identified a highly novel concept where Brucella utilizes blue light to increase its virulence similar to some plant bacterial pathogens. Further, our studies have revealed bacterial second messengers that regulate virulence, quorum sensing mechanisms permitting bacteria to evaluate their environment, and a genomic island that controls synthesis of its lipopolysaccharide surface. Discussions are ongoing with a vaccine company for application of this genomic island knowledge in a Brucella vaccine by the U.S. lab. Also, our new technology of bioengineering bioluminescent Brucella has resulted in a spin-off application for diagnosis of Brucella infected animals by the Israeli lab by prioritizing bacterial diagnosis over serological diagnosis.

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