Journal articles: 'Homing sequence'

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Takai, Ken, and Koki Horikoshi. "Molecular Phylogenetic Analysis of Archaeal Intron-Containing Genes Coding for rRNA Obtained from a Deep-Subsurface Geothermal Water Pool." Applied and Environmental Microbiology 65, no. 12 (December 1, 1999): 5586–89. http://dx.doi.org/10.1128/aem.65.12.5586-5589.1999.

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ABSTRACT Molecular phylogenetic analysis of a naturally occurring microbial community in a deep-subsurface geothermal environment indicated that the phylogenetic diversity of the microbial population in the environment was extremely limited and that only hyperthermophilic archaeal members closely related to Pyrobaculum were present. All archaeal ribosomal DNA sequences contained intron-like sequences, some of which had open reading frames with repeated homing-endonuclease motifs. The sequence similarity analysis and the phylogenetic analysis of these homing endonucleases suggested the possible phylogenetic relationship among archaeal rRNA-encoded homing endonucleases.

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Bochtler, Matthias. "Indirect DNA Sequence Readout by LAGLIDADG Homing Endonucleases." Structure 24, no. 6 (June 2016): 839–40. http://dx.doi.org/10.1016/j.str.2016.05.008.

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Alloatti, Domenico, Giuseppe Giannini, Loredana Vesci, Massimo Castorina, Claudio Pisano, Elena Badaloni, and Walter Cabri. "Camptothecins in tumor homing via an RGD sequence mimetic." Bioorganic & Medicinal Chemistry Letters 22, no. 20 (October 2012): 6509–12. http://dx.doi.org/10.1016/j.bmcl.2012.07.061.

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Sibrian-Vazquez, Martha, Xiaoke Hu, Timothy J. Jensen, and M. Graça H. Vicente. "Synthesis and cellular studies of PPIX-homing peptide conjugates." Journal of Porphyrins and Phthalocyanines 16, no. 05n06 (May 2012): 603–15. http://dx.doi.org/10.1142/s1088424612500599.

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Five amphiphilic protoporphyrin IX-peptide conjugates bearing the sequences ATWLPPR, AAhexPQRRSARLSA and cERGDPhe conjugated via the propionic side chains, were synthesized and evaluated in vitro using two cell lines: human carcinoma HEp2 and human leukemia HL-60. All conjugates were found to have low dark- and photo-toxicities in both cell lines, and 3 to 10-fold higher accumulation was observed within HL-60 vs. HEp2 cells, depending on the nature of the peptide sequence. The preferential subcellular sites of localization for all conjugates were found to be the lysosomes in HEp2 cells, and the mitochondria in HL-60 cells, suggesting different mechanisms of cellular internalization.

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Birgisdottir, Å. B., and S. D. Johansen. "Reverse splicing of a mobile twin-ribozyme group I intron into the natural small subunit rRNA insertion site." Biochemical Society Transactions 33, no. 3 (June 1, 2005): 482–84. http://dx.doi.org/10.1042/bst0330482.

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A mobile group I intron containing two ribozyme domains and a homing endonuclease gene (twin-ribozyme intron organization) can integrate by reverse splicing into the small subunit rRNA of bacteria and yeast. The integration is sequence-specific and corresponds to the natural insertion site (homing site) of the intron. The reverse splicing is independent of the homing endonuclease gene, but is dependent on the group I splicing ribozyme domain. The observed distribution of group I introns in nature can be explained by horizontal transfer between natural homing sites by reverse splicing and subsequent spread in populations by endonuclease-dependent homing.

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Scalley-Kim, Michelle, Audrey McConnell-Smith, and Barry L. Stoddard. "Coevolution of a Homing Endonuclease and Its Host Target Sequence." Journal of Molecular Biology 372, no. 5 (October 2007): 1305–19. http://dx.doi.org/10.1016/j.jmb.2007.07.052.

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Tvardovskii, Aleksandr Sergeevich, and Nina Vladimirovna Yevtushenko. "Deriving Homing Sequences for Finite State Machines with Timed Guards." Modeling and Analysis of Information Systems 27, no. 4 (December 20, 2020): 376–95. http://dx.doi.org/10.18255/1818-1015-2020-4-376-395.

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State identification is the well-known problem in the theory of Finite State Machines (FSM) where homing sequences (HS) are used for the identification of a current FSM state, and this fact is widely used in the area of software and hardware testing and verification. For various kinds of FSMs, such as partial, complete, deterministic, non-deterministic, there exist sufficient and necessary conditions for the existence ofpreset and adaptive HS and algorithms for their derivation. Nowadays timed aspects become very important for hardware and software systems and for this reason classical FSMs are extended by clock variables. In this work, we address the problem of checking the existence and derivation of homing sequences for FSMs with timed guards and show that the length estimation for timed homing sequence coincides with that for untimed FSM. The investigation is based on the FSM abstraction of a Timed FSM, i.e. on a classical FSM which describes behavior of corresponding TFSM and inherits some of its properties. When solving state identification problems for timed FSMs, the existing FSM abstraction is properly optimized.

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Wuitschick, Jeffrey D., Paul R. Lindstrom, Alison E. Meyer, and Kathleen M. Karrer. "Homing Endonucleases Encoded by Germ Line-Limited Genes in Tetrahymena thermophila Have APETELA2 DNA Binding Domains." Eukaryotic Cell 3, no. 3 (June 2004): 685–94. http://dx.doi.org/10.1128/ec.3.3.685-694.2004.

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ABSTRACT Three insertion elements were previously found in a family of germ line-limited mobile elements, the Tlr elements, in the ciliate Tetrahymena. Each of the insertions contains an open reading frame (ORF). Sequence analysis of the deduced proteins encoded by the elements suggests that they are homing endonucleases. The genes are designated TIE1-1, TIE2-1, and TIE3-1 for Tetrahymena insertion-homing endonuclease. The endonuclease motif occupies the amino terminal half of each TIE protein. The C-terminal regions of the proteins are similar to the APETELA2 DNA binding domain of plant transcription factors. The TIE1 and TIE3 elements belong to families of repeated sequences in the germ line micronuclear genome. Comparison of the genes and the deduced proteins they encode suggests that there are at least two distinct families of homing endonuclease genes, each of which appears to be preferentially associated with a specific region of the Tlr elements. The TIE1 and TIE3 elements and their cognates undergo programmed elimination from the developing somatic macronucleus of Tetrahymena. The possible role of homing endonuclease-like genes in the DNA breakage step in developmentally programmed DNA elimination in Tetrahymena is discussed.

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MacGregor, Barbara J., Jennifer F. Biddle, and Andreas Teske. "Mobile Elements in a Single-Filament Orange Guaymas Basin Beggiatoa (“Candidatus Maribeggiatoa”) sp. Draft Genome: Evidence for Genetic Exchange with Cyanobacteria." Applied and Environmental Microbiology 79, no. 13 (April 19, 2013): 3974–85. http://dx.doi.org/10.1128/aem.03821-12.

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ABSTRACTThe draft genome sequence of a single orangeBeggiatoa(“CandidatusMaribeggiatoa”) filament collected from a microbial mat at a hydrothermal site in Guaymas Basin (Gulf of California, Mexico) shows evidence of extensive genetic exchange with cyanobacteria, in particular for sensory and signal transduction genes. A putative homing endonuclease gene and group I intron within the 23S rRNA gene; several group II catalytic introns; GyrB and DnaE inteins, also encoding homing endonucleases; multiple copies of sequences similar to thefdxNexcision elements XisH and XisI (required for heterocyst differentiation in some cyanobacteria); and multiple sequences related to an open reading frame (ORF) (00024_0693) of unknown function all have close non-Beggiatoaceaematches with cyanobacterial sequences. Sequences similar to the uncharacterized ORF and Xis elements are found in otherBeggiatoaceaegenomes, a variety of cyanobacteria, and a few phylogenetically dispersed pleiomorphic or filamentous bacteria. We speculate that elements shared among filamentous bacterial species may have been exchanged in microbial mats and that some of them may be involved in cell differentiation.

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Chen, Z., F. Wen, N. Sun, and H. Zhao. "Directed evolution of homing endonuclease I-SceI with altered sequence specificity." Protein Engineering Design and Selection 22, no. 4 (January 10, 2009): 249–56. http://dx.doi.org/10.1093/protein/gzp001.

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Nord, David, Eduard Torrents, and Britt-Marie Sjöberg. "A Functional Homing Endonuclease in the Bacillus anthracis nrdE Group I Intron." Journal of Bacteriology 189, no. 14 (May 11, 2007): 5293–301. http://dx.doi.org/10.1128/jb.00234-07.

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ABSTRACT The essential Bacillus anthracis nrdE gene carries a self-splicing group I intron with a putative homing endonuclease belonging to the GIY-YIG family. Here, we show that the nrdE pre-mRNA is spliced and that the homing endonuclease cleaves an intronless nrdE gene 5 nucleotides (nt) upstream of the intron insertion site, producing 2-nt 3′ extensions. We also show that the sequence required for efficient cleavage spans at least 4 bp upstream and 31 bp downstream of the cleaved coding strand. The position of the recognition sequence in relation to the cleavage position is as expected for a GIY-YIG homing endonuclease. Interestingly, nrdE genes from several other Bacillaceae were also susceptible to cleavage, with those of Bacillus cereus, Staphylococcus epidermidis (nrdE1), B. anthracis, and Bacillus thuringiensis serovar konkukian being better substrates than those of Bacillus subtilis, Bacillus lichenformis, and S. epidermidis (nrdE2). On the other hand, nrdE genes from Lactococcus lactis, Escherichia coli, Salmonella enterica serovar Typhimurium, and Corynebacterium ammoniagenes were not cleaved. Intervening sequences (IVSs) residing in protein-coding genes are often found in enzymes involved in DNA metabolism, and the ribonucleotide reductase nrdE gene is a frequent target for self-splicing IVSs. A comparison of nrdE genes from seven gram-positive low-G+C bacteria, two bacteriophages, and Nocardia farcinica showed five different insertion sites for self-splicing IVSs within the coding region of the nrdE gene.

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Furulund, Betty M. N., Bård O. Karlsen, Igor Babiak, and Steinar D. Johansen. "A Phylogenetic Approach to Structural Variation in Organization of Nuclear Group I Introns and Their Ribozymes." Non-Coding RNA 7, no. 3 (July 22, 2021): 43. http://dx.doi.org/10.3390/ncrna7030043.

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Nuclear group I introns are restricted to the ribosomal DNA locus where they interrupt genes for small subunit and large subunit ribosomal RNAs at conserved sites in some eukaryotic microorganisms. Here, the myxomycete protists are a frequent source of nuclear group I introns due to their unique life strategy and a billion years of separate evolution. The ribosomal DNA of the myxomycete Mucilago crustacea was investigated and found to contain seven group I introns, including a direct repeat-containing intron at insertion site S1389 in the small subunit ribosomal RNA gene. We collected, analyzed, and compared 72 S1389 group IC1 introns representing diverse myxomycete taxa. The consensus secondary structure revealed a conserved ribozyme core, but with surprising sequence variations in the guanosine binding site in segment P7. Some S1389 introns harbored large extension sequences in the peripheral region of segment P9 containing direct repeat arrays. These repeats contained up to 52 copies of a putative internal guide sequence motif. Other S1389 introns harbored homing endonuclease genes in segment P1 encoding His-Cys proteins. Homing endonuclease genes were further interrupted by small spliceosomal introns that have to be removed in order to generate the open reading frames. Phylogenetic analyses of S1389 intron and host gene indicated both vertical and horizontal intron transfer during evolution, and revealed sporadic appearances of direct repeats, homing endonuclease genes, and guanosine binding site variants among the myxomycete taxa.

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Fu, Yu, Tien-Ruey Hsiang, and Sheng-Luen Chung. "Multi-waypoint visual homing in piecewise linear trajectory." Robotica 31, no. 3 (August 16, 2012): 479–91. http://dx.doi.org/10.1017/s0263574712000434.

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SUMMARYThis paper proposes an image sequence-based navigation method under the teaching-replay framework for robots in piecewise linear routes. Waypoints used by the robot contain either the positions with large heading changes or selected midway positions between junctions. The robot applies local visual homing to move between consecutive waypoints. The arrival at a waypoint is determined by minimizing the average vertical displacements of feature correspondences. The performance of the proposed approach is supported by extensive experiments in hallway and office environments. While the homing speed of robots using other approaches is constrained by the speed in the teaching phase, our robot is not bounded by such limit and can travel much faster without compromising the homing accuracy.

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Flack, Andrea, Tim Guilford, and Dora Biro. "Learning multiple routes in homing pigeons." Biology Letters 10, no. 4 (April 2014): 20140119. http://dx.doi.org/10.1098/rsbl.2014.0119.

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The aerial lifestyle of central-place foraging birds allows wide-ranging movements, raising fundamental questions about their remarkable navigation and memory systems. For example, we know that pigeons ( Columba livia ), long-standing models for avian navigation, rely on individually distinct routes when homing from familiar sites. But it remains unknown how they cope with the task of learning several routes in parallel. Here, we examined how learning multiple routes influences homing in pigeons. We subjected groups of pigeons to different training protocols, defined by the sequence in which they were repeatedly released from three different sites, either sequentially, in rotation or randomly. We observed that pigeons from all groups successfully developed and applied memories of the different release sites (RSs), irrespective of the training protocol, and that learning several routes in parallel did not impair their capacity to quickly improve their homing efficiency over multiple releases. Our data also indicated that they coped with increasing RS uncertainty by adjusting both their initial behaviour upon release and subsequent homing efficiency. The results of our study broaden our understanding of avian route following and open new possibilities for studying learning and memory in free-flying animals.

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Pingoud, Vera, Hubert Thole, Frauke Christ, Wolfgang Grindl, Wolfgang Wende, and Alfred Pingoud. "Photocross-linking of the Homing Endonuclease PI-SceI to Its Recognition Sequence." Journal of Biological Chemistry 274, no. 15 (April 9, 1999): 10235–43. http://dx.doi.org/10.1074/jbc.274.15.10235.

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Seligman, Lenny M., Kathryn M. Stephens, Jeremiah H. Savage, and Raymond J. Monnat. "Genetic Analysis of the Chlamydomonas reinhadtii I-CreI Mobile Intron Homing System in Escherichia coli." Genetics 147, no. 4 (December 1, 1997): 1653–64. http://dx.doi.org/10.1093/genetics/147.4.1653.

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Abstract We have developed and used a genetic selection system in Escherichia coli to study functional requirements for homing site recognition and cleavage by a representative eukaryotic mobile intron endonuclease. The homing endonuclease, I-CreI, was originally isolated from the chloroplast of the unicellular green alga Chlamydomonas reinhardtii. I-CreI homing site mutants contained base pair substitutions or single base deletions that altered the rate of homing site cleavage and/or product release. I-CreI endonuclease mutants fell into six phenotypic classes that differed in in vivo activity, toxicity or genetic dominance. Inactivating mutations clustered in the N-terminal 60% of the I-CreI amino acid sequence, and two frameshift mutations were isolated that resulted in premature translation termination though retained partial activity. These mutations indicate that the N-terminal two-thirds of the I-CreI endonuclease is sufficient for homing site recognition and cleavage. Substitution mutations altered in four potential active site residues were examined D20N, Q47H or R70A substitutions inactivated endonuclease activity, whereas S22A did not. The genetic approach we have taken complements phylogenetic and structural studies of mobile intron endonucleases and has provided new information on the mechanistic basis of I-CreI homing site recognition and cleavage.

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Bowen, B. R., T. Nguyen, and L. A. Lasky. "Characterization of a human homologue of the murine peripheral lymph node homing receptor." Journal of Cell Biology 109, no. 1 (July 1, 1989): 421–27. http://dx.doi.org/10.1083/jcb.109.1.421.

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Lymphocyte trafficking is a fundamental aspect of the immune system that allows B and T lymphocytes with diverse antigen recognition specificities to be exposed to various antigenic stimuli in spatially distinct regions of an organism. A lymphocyte adhesion molecule that is involved with this trafficking phenomenon has been termed the homing receptor. Previous work (Lasky, L., T. Yednock, M. Singer, D. Dowbenko, C. Fennie, H. Rodriguez, T. Nguyen, S. Stachel, and S. Rosen. 1989. Cell. 56:1045-1055) has characterized a cDNA clone encoding a murine homing receptor that is involved in trafficking of lymphocytes to peripheral lymph nodes. This molecule was found to contain a number of protein motifs, the most intriguing of which was a carbohydrate binding domain, or lectin, that is apparently involved in the adhesive interaction between murine lymphocytes and peripheral lymph node endothelium. In this study, we have used the murine cDNA clone to isolate a human homologue of this peripheral lymph node-specific adhesion molecule. The human receptor was found to be highly homologous to the murine receptor in overall sequence, but showed no sequence similarity to another surface protein that may be involved with human lymphocyte homing, the Hermes glycoprotein. The extracellular region of the human receptor contained an NH2 terminally located carbohydrate binding domain followed by an EGF-like domain and a domain containing two repeats of a complement binding motif. Transient cell transfection assays using the human receptor cDNA showed that it encoded a surface glycoprotein that cross reacted with a polyclonal antibody directed against the murine peripheral lymph node homing receptor. Interestingly, the human receptor showed a high degree of sequence homology to another human cell adhesion glycoprotein, the endothelial cell adhesion molecule ELAM.

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Sitbon, Einat, and Shmuel Pietrokovski. "New types of conserved sequence domains in DNA-binding regions of homing endonucleases." Trends in Biochemical Sciences 28, no. 9 (September 2003): 473–77. http://dx.doi.org/10.1016/s0968-0004(03)00170-1.

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Morin, Ryan D., Karen Mungall, Erin Pleasance, Andrew J. Mungall, Rodrigo Goya, Ryan D. Huff, David W. Scott, et al. "Mutational and structural analysis of diffuse large B-cell lymphoma using whole-genome sequencing." Blood 122, no. 7 (August 15, 2013): 1256–65. http://dx.doi.org/10.1182/blood-2013-02-483727.

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Key Points Complete genome sequence analysis of 40 DLBCL tumors and 13 cell lines reveals novel somatic point mutations, rearrangements, and fusions. Recurrence of mutations in genes involved in B-cell homing were identified in germinal center B-cell DLBCLs.

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Fukuda, Tomoyuki, Kunihiro Ohta, and Yoshikazu Ohya. "Investigation of the Mechanism of Meiotic DNA Cleavage by VMA1-Derived Endonuclease Uncovers a Meiotic Alteration in Chromatin Structure around the Target Site." Eukaryotic Cell 5, no. 6 (June 2006): 981–90. http://dx.doi.org/10.1128/ec.00052-06.

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ABSTRACT VMA1-derived endonuclease (VDE), a homing endonuclease in Saccharomyces cerevisiae, is encoded by the mobile intein-coding sequence within the nuclear VMA1 gene. VDE recognizes and cleaves DNA at the 31-bp VDE recognition sequence (VRS) in the VMA1 gene lacking the intein-coding sequence during meiosis to insert a copy of the intein-coding sequence at the cleaved site. The mechanism underlying the meiosis specificity of VMA1 intein-coding sequence homing remains unclear. We studied various factors that might influence the cleavage activity in vivo and found that VDE binding to the VRS can be detected only when DNA cleavage by VDE takes place, implying that meiosis-specific DNA cleavage is regulated by the accessibility of VDE to its target site. As a possible candidate for the determinant of this accessibility, we analyzed chromatin structure around the VRS and revealed that local chromatin structure near the VRS is altered during meiosis. Although the meiotic chromatin alteration exhibits correlations with DNA binding and cleavage by VDE at the VMA1 locus, such a chromatin alteration is not necessarily observed when the VRS is embedded in ectopic gene loci. This suggests that nucleosome positioning or occupancy around the VRS by itself is not the sole mechanism for the regulation of meiosis-specific DNA cleavage by VDE and that other mechanisms are involved in the regulation.

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Barzel, Adi, Adit Naor, Eyal Privman, Martin Kupiec, and Uri Gophna. "Homing endonucleases residing within inteins: evolutionary puzzles awaiting genetic solutions." Biochemical Society Transactions 39, no. 1 (January 19, 2011): 169–73. http://dx.doi.org/10.1042/bst0390169.

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Inteins are selfish genetic elements that disrupt the sequence of protein-coding genes and are excised post-translationally. Most inteins also contain a HEN (homing endonuclease) domain, which is important for their horizontal transmission. The present review focuses on the evolution of inteins and their nested HENs, and highlights several unsolved questions that could benefit from molecular genetic approaches. Such approaches can be well carried out in halophilic archaea, which are naturally intein-rich and have highly developed genetic tools for their study. In particular, the fitness effects of habouring an intein/HEN can be tested in direct competition assays, providing additional insights that will improve current evolutionary models.

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Theodoro, Raquel Cordeiro, Gerrit Volkmann, Xiang-Qin Liu, and Eduardo Bagagli. "PRP8 intein in Ajellomycetaceae family pathogens: Sequence analysis, splicing evaluation and homing endonuclease activity." Fungal Genetics and Biology 48, no. 2 (February 2011): 80–91. http://dx.doi.org/10.1016/j.fgb.2010.07.010.

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Sandegren, Linus, and Britt-Marie Sjöberg. "Distribution, Sequence Homology, and Homing of Group I Introns among T-even-like Bacteriophages." Journal of Biological Chemistry 279, no. 21 (March 15, 2004): 22218–27. http://dx.doi.org/10.1074/jbc.m400929200.

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Moure, Carmen M., Frederick S. Gimble, and Florante A. Quiocho. "Crystal structure of the intein homing endonuclease PI-SceI bound to its recognition sequence." Nature Structural Biology 9, no. 10 (September 3, 2002): 764–70. http://dx.doi.org/10.1038/nsb840.

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Gimble, F. S. "Degeneration of a homing endonuclease and its target sequence in a wild yeast strain." Nucleic Acids Research 29, no. 20 (October 15, 2001): 4215–23. http://dx.doi.org/10.1093/nar/29.20.4215.

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Wilson, S., D. A. Tonge, and N. Holder. "Homing behaviour of regenerating axons in the amphibian limb." Development 106, no. 4 (August 1, 1989): 707–15. http://dx.doi.org/10.1242/dev.106.4.707.

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Following peripheral nerve deviation in the limbs of urodele amphibians axons regrow distally toward their previous target muscles (Holder et al. 1984; Proc. Roy. Soc. Lond. B 222, 477–489). This study describes analysis of this axon regeneration over time following deviation of the forearm flexor nerve in Triturus cristatus and the extensor cranialis nerve in the axolotl. Using horseradish peroxidase (HRP) axonal tracing, electrophysiology and electron microscopy, we describe the sequence of events leading to reestablishment of functional innervation. HRP fills reveal axons leaving the deviated nerve via a number of possible routes and they invariably grow distally. Many axons take a path close to that of the original nerve but others fasciculate forming parallel paths. Electrophysiology and electron microscopy show that axons in the deviated region of the nerve degenerate extensively compared with cut, but undeviated, controls. The results are discussed in terms of the possible axon-growth-promoting mechanisms that result in directed growth.

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Dybus, Andrzej, Hanna Kulig, Yu-Hsiang Yu, Ruben Lanckriet, Witold Proskura, and Yeong-Hsiang Cheng. "CRY1 Gene Polymorphism and Racing Performance of Homing Pigeons." Animals 11, no. 9 (September 7, 2021): 2632. http://dx.doi.org/10.3390/ani11092632.

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Cryptochromes (CRY) are the family of proteins proposed as the putative magnetoreceptor molecules. In birds, among others in pigeons, CRY1 is widely expressed in a retina. Homing pigeons are known for their navigational abilities, and pigeon racing is a popular sport. So, the purpose of this study was to analyze the variability of the nucleotide sequence of the homing pigeon CRY1 gene, spanning the region coding the two amino acids W320 and W374 of Trp-triad, and estimate the relationship between genotypes and the racing performance. Investigations were carried out on 129 pigeons. Analysis of sequencing results indicated the AG to TT change within the seventh intron of CRY1 gene. Genotypes were determined by the forced PCR-RFLP method. The influence of detected polymorphism on the results of racing pigeons in 100–400 km flights was shown. The AG/TT individuals achieved significantly higher (p ≤ 0.05) mean values of ace points (AP) than the AG/AG ones. Regarding the detected nucleotide change localization, the polymorphism may be involved in CRY1 gene expression modulation. The AG to TT change in CRY1 gene may be considered as a potential genetic marker of racing performance in homing pigeons.

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Bilto, Iman M., Tuhin K. Guha, Alvan Wai, and Georg Hausner. "Three new active members of the I-OnuI family of homing endonucleases." Canadian Journal of Microbiology 63, no. 8 (August 2017): 671–81. http://dx.doi.org/10.1139/cjm-2017-0067.

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In vitro characterization of 3 LAGLIDADG-type homing endonucleases (HEs) (I-CcaI, I-CcaII, and I-AstI) that belong to the I-OnuI family showed that they are functional HEs that cleave their respective cognate target sites. These endonucleases are encoded within group ID introns and appear to be orthologues that have inserted into 3 different mitochondrial genes: rns, rnl, and cox3. The endonuclease activity of I-CcaI was tested using various substrates, and its minimum DNA recognition sequence was estimated to be 26 nt. This set of HEs may provide some insight into how these types of mobile elements can migrate into new locations. This study provides additional endonucleases that can be added to the catalog of currently available HEs that may have various biotechnology applications.

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Imai, Y., D. D. True, M. S. Singer, and S. D. Rosen. "Direct demonstration of the lectin activity of gp90MEL, a lymphocyte homing receptor." Journal of Cell Biology 111, no. 3 (September 1, 1990): 1225–32. http://dx.doi.org/10.1083/jcb.111.3.1225.

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Considerable evidence implicates gp90MEL as a lymphocyte homing receptor mediating lymphocyte attachment to high endothelial venules of lymph nodes in mouse. The protein appears to function as a calcium-dependent, lectin-like receptor as inferred primarily by the ability of specific carbohydrates to block its function and by the presence of a calcium-type lectin domain in its primary sequence. An ELISA assay is described which provides the first demonstration that the isolated protein has lectin activity and allows a further definition of its carbohydrate specificity. In addition to the monosaccharides mannose-6-phosphate and fructose-1-phosphate, ligand activity is shown for the sulfated glycolipid, sulfatide, and for two sulfated fucose-containing polysaccharides (fucoidin and egg jelly coat) from nonmammalian sources.

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Sandoval, Cristina M., Bernhard H. Geierstanger, Satoshi Fujimura, Calvin Balatbat, Taylor Williams, Julio de Unamuno, Jennifer A. Whiles-Lillig, et al. "Structural Evaluation of a Novel Pro-apoptotic Peptide Coupled to CNGRC Tumor Homing Sequence by NMR." Chemical Biology & Drug Design 67, no. 6 (June 2006): 417–24. http://dx.doi.org/10.1111/j.1747-0285.2006.00394.x.

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Xu, Shuang-yong. "Sequence-specific DNA nicking endonucleases." Biomolecular Concepts 6, no. 4 (August 1, 2015): 253–67. http://dx.doi.org/10.1515/bmc-2015-0016.

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AbstractA group of small HNH nicking endonucleases (NEases) was discovered recently from phage or prophage genomes that nick double-stranded DNA sites ranging from 3 to 5 bp in the presence of Mg2+ or Mn2+. The cosN site of phage HK97 contains a gp74 nicking site AC↑CGC, which is similar to AC↑CGR (R=A/G) of N.ϕGamma encoded by Bacillus phage Gamma. A minimal nicking domain of 76 amino acid residues from N.ϕGamma could be fused to other DNA binding partners to generate chimeric NEases with new specificities. The biological roles of a few small HNH endonucleases (HNHE, gp74 of HK97, gp37 of ϕSLT, ϕ12 HNHE) have been demonstrated in phage and pathogenicity island DNA packaging. Another group of NEases with 3- to 7-bp specificities are either natural components of restriction systems or engineered from type IIS restriction endonucleases. A phage group I intron-encoded HNH homing endonucleases, I-PfoP3I was found to nick DNA sites of 14–16 bp. I-TslI encoded by T7-like ΦI appeared to nick DNA sites with a 9-bp core sequence. DNA nicking and labeling have been applied to optical mapping to aid genome sequence assembly and detection of large insertion/deletion mutations in genomic DNA of cancer cells. Nicking enzyme-mediated amplification reaction has been applied to rapid diagnostic testing of influenza A and B in clinical setting and for construction of DNA-based Boolean logic gates. The clustered regularly interspaced short palindromic repeats-ribonucleoprotein complex consisting of engineered Cas9 nickases in conjunction with tracerRNA:crRNA or a single-guide RNA have been successfully used in genome modifications.

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Schwarz, Sebastian, Michael Mangan, Barbara Webb, and Antoine Wystrach. "Route-following ants respond to alterations of the view sequence." Journal of Experimental Biology 223, no. 14 (June 2, 2020): jeb218701. http://dx.doi.org/10.1242/jeb.218701.

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ABSTRACTAnts can navigate by comparing the currently perceived view with memorised views along a familiar foraging route. Models regarding route-following suggest that the views are stored and recalled independently of the sequence in which they occur. Hence, the ant only needs to evaluate the instantaneous familiarity of the current view to obtain a heading direction. This study investigates whether ant homing behaviour is influenced by alterations in the sequence of views experienced along a familiar route, using the frequency of stop-and-scan behaviour as an indicator of the ant's navigational uncertainty. Ants were trained to forage between their nest and a feeder which they exited through a short channel before proceeding along the homeward route. In tests, ants were collected before entering the nest and released again in the channel, which was placed either in its original location or halfway along the route. Ants exiting the familiar channel in the middle of the route would thus experience familiar views in a novel sequence. Results show that ants exiting the channel scan significantly more when they find themselves in the middle of the route, compared with when emerging at the expected location near the feeder. This behaviour suggests that previously encountered views influence the recognition of current views, even when these views are highly familiar, revealing a sequence component to route memory. How information about view sequences could be implemented in the insect brain, as well as potential alternative explanations to our results, are discussed.

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Umikawa, Masato, Junke Zheng, HoangDinh Huynh, and Chengcheng Zhang. "Angiopoietin-Like 3 Affects Homing Ability of Hematopoietic Stem Cells." Blood 116, no. 21 (November 19, 2010): 2632. http://dx.doi.org/10.1182/blood.v116.21.2632.2632.

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Abstract Abstract 2632 Angiopoietin-like proteins (Angptls) are a seven-member family of secreted glycoproteins that share sequence homology with angiopoietins. It is known that several members of the Angptl family including Angptl3 support ex vivo expansion of hematopoietic stem cells (HSCs). However, the physiological role of Angptls in the hematopoietic system is not well known. Here we show that Angptl3 is expressed by both bone marrow stromal cells and HSCs. To study the intrinsic effect of Angptl3 in mouse HSCs, we isolated the same number of HSCs from wild-type and Angptl3-null mice and performed reconstitution analysis. Adult bone marrow Angptl3-null HSCs showed decreased repopulation compared to wild-type HSCs, suggesting that Angptl3 has cell-autonomous effect on HSC activity. By contrast, HSCs isolated from liver of the null mice had enhanced HSC repopulation activity than their wild-type counterparts. To study whether this effect is caused by difference in homing, we injected CFSE labeled wild-type HSCs and Angptl3 null HSCs into lethally irradiated mice, and checked the homing to bone marrow, spleen, and liver. While homing of these two types of cells to bone marrow or spleen was not significantly different, Angptl3 null HSCs homed better to the liver than the wild-type HSCs. Our result suggests that Angptl3 is important for the retention of HSCs in the bone marrow, and the absence of Angptl3 leads HSCs to move to extramedullary organs such as liver. Disclosures: No relevant conflicts of interest to declare.

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Chen, Xu Qin, and Guang Zhen Cheng. "PLC Control System of the Stage Loader Based on Step Ladder Instruction." Applied Mechanics and Materials 201-202 (October 2012): 442–45. http://dx.doi.org/10.4028/www.scientific.net/amm.201-202.442.

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The purpose of this paper is to design an electric control system of stage loader which has clear logical relations and is easy to operate. The control system improved the working reliability of electric control system. Taking stage loader used in coal storage yard as an example, we introduce the mechanical structure and working principle of stage loader, mainly discuss about the components of electric control system, the action sequence of the actuator, electrical control PLC program .This paper pointes out that the use of step ladder instruction can make logical relations of action sequence clear and the use of state initialization instruction can make the state transitions among manual program, homing procedure, automatic continuous working procedure simple.

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Párraga, Daniel García, Peter L. Tyack, Vicente Marco-Cabedo, José Luis Crespo-Picazo, Xavier Manteca, and Luis Martí-Bonmatí. "Effects of 3 Tesla magnetic resonance imaging exposure on the behavior and orientation of homing pigeons Columba livia domestica." PLOS ONE 15, no. 12 (December 18, 2020): e0241280. http://dx.doi.org/10.1371/journal.pone.0241280.

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Homing pigeons (Columba livia domestica) were used to test whether clinical magnetic resonance (MR) imaging disrupts orientation of animals that sense the earth’s magnetic field. Thirty young pigeons were randomly separated into three groups (n = 10/group). Two groups were anaesthetized and exposed to either a constant (no sequence) or a varying (gradient echo and echo planar sequences) magnetic field within a 3 Tesla MR unit for 15 minutes. The control group was not exposed to the MR field but shared all other aspects of the procedure. One day later, animals were released from a site they had never visited, 15 km from the home loft. Three weeks after the procedure, animals were released from a different unfamiliar site 30 km from the loft. Measured variables included the time to disappear from sight (seconds), vanishing bearing (angle), and the time interval from release to entering the home loft (hours). On first release, the group exposed to varying field gradients during image acquisition using 2 different standard sequences showed more variability in the vanishing bearing compared to the other groups (p = 0.0003 compared to control group), suggesting interference with orientation. Other measures did not show significant differences between groups. On second release, there were no significant differences between groups. Our results on homing pigeons show that regular clinical MR imaging exposure may temporarily affect the orientation of species that have magnetoreception capabilities. If exposure to MR imaging disrupted processes that are not specific to magnetoreception, then it may affect other species and other capabilities as well.

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Bakhrat, Anya, Melissa S. Jurica, Barry L. Stoddard, and Dina Raveh. "Homology Modeling and Mutational Analysis of Ho Endonuclease of Yeast." Genetics 166, no. 2 (February 1, 2004): 721–28. http://dx.doi.org/10.1093/genetics/166.2.721.

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Abstract Ho endonuclease is a LAGLIDADG homing endonuclease that initiates mating-type interconversion in yeast. Ho is encoded by a free-standing gene but shows 50% primary sequence similarity to the intein (protein-intron encoded) PI-SceI. Ho is unique among LAGLIDADG endonucleases in having a 120-residue C-terminal putative zinc finger domain. The crystal structure of PI-SceI revealed a bipartite enzyme with a protein-splicing domain (Hint) and intervening endonuclease domain. We made a homology model for Ho on the basis of the PI-SceI structure and performed mutational analysis of putative critical residues, using a mating-type switch as a bioassay for activity and GFP-fusion proteins to detect nuclear localization. We found that residues of the N-terminal sequence of the Hint domain are important for Ho activity, in particular the DNA recognition region. C-terminal residues of the Hint domain are dispensable for Ho activity; however, the C-terminal putative zinc finger domain is essential. Mutational analysis indicated that residues in Ho that are conserved relative to catalytic, active-site residues in PI-SceI and other related homing endonucleases are essential for Ho activity. Our results indicate that in addition to the conserved catalytic residues, Hint domain residues and the zinc finger domain have evolved a critical role in Ho activity.

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Buehler, Alexandra, Marc A. M. J. van Zandvoort, Bram J. Stelt, Tilman M. Hackeng, Bianca H. G. J. Schrans-Stassen, Abdelkader Bennaghmouch, Leo Hofstra, et al. "cNGR: A Novel Homing Sequence for CD13/APN Targeted Molecular Imaging of Murine Cardiac Angiogenesis In Vivo." Arteriosclerosis, Thrombosis, and Vascular Biology 26, no. 12 (December 2006): 2681–87. http://dx.doi.org/10.1161/01.atv.0000245807.65714.0b.

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Neuhaus, H., M. C. Hu, M. E. Hemler, Y. Takada, B. Holzmann, and I. L. Weissman. "Cloning and expression of cDNAs for the alpha subunit of the murine lymphocyte-Peyer's patch adhesion molecule." Journal of Cell Biology 115, no. 4 (November 15, 1991): 1149–58. http://dx.doi.org/10.1083/jcb.115.4.1149.

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cDNA clones encoding the alpha chain of the murine lymphocyte-Peyer's patch adhesion molecule (LPAM), which is associated with lymphocyte homing, have been isolated by screening with the human VLA-4 (alpha 4h) probe. Several alpha 4 antigenic determinants were identified on COS-7 cells after transfection. From overlapping clones, approximately 5 kb of contiguous nucleotide sequence have been determined, encoding a protein sequence of 1039 amino acids for the LPAM alpha chain (alpha 4m). LPAM is a member of the integrin family of cell-surface heterodimers, and alpha 4m is the murine homologue of the human alpha 4 h chain. The two proteins have a total sequence similarity of 84%, with an almost perfect conservation (31/32 amino acids) in the cytoplasmic domain. Like alpha 4h, alpha 4m is distinct from other integrin alpha chains because it has neither an I-domain nor a COOH-terminal cleavage site. The positions of the characteristic Cysteine residues are conserved, and a putative protease cleavage site is located near the middle of the protein sequence. The NH2-terminal part of the protein contains seven homologous repeats, and three of them include putative divalent cation-binding sites. These sites are among the most conserved between the alpha 4m sequence and other alpha chains, and may therefore be involved in the binding of integrin alpha and beta chains. An additional cDNA clone was isolated which shares a sequence of perfect homology with the alpha 4m encoding cDNAs, but has a unique 3' poly-A end. This observation correlates with the fact that three discrete murine RNA bands are observed in Northern blot experiments using alpha 4m as a probe, whereas only two human RNA species are described for alpha 4h, indicating a higher complexity for murine than for human sequences.

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Fuchs, Silke, William T. Garrood, Anna Beber, Andrew Hammond, Roberto Galizi, Matthew Gribble, Giulia Morselli, et al. "Resistance to a CRISPR-based gene drive at an evolutionarily conserved site is revealed by mimicking genotype fixation." PLOS Genetics 17, no. 10 (October 5, 2021): e1009740. http://dx.doi.org/10.1371/journal.pgen.1009740.

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CRISPR-based homing gene drives can be designed to disrupt essential genes whilst biasing their own inheritance, leading to suppression of mosquito populations in the laboratory. This class of gene drives relies on CRISPR-Cas9 cleavage of a target sequence and copying (‘homing’) therein of the gene drive element from the homologous chromosome. However, target site mutations that are resistant to cleavage yet maintain the function of the essential gene are expected to be strongly selected for. Targeting functionally constrained regions where mutations are not easily tolerated should lower the probability of resistance. Evolutionary conservation at the sequence level is often a reliable indicator of functional constraint, though the actual level of underlying constraint between one conserved sequence and another can vary widely. Here we generated a novel adult lethal gene drive (ALGD) in the malaria vector Anopheles gambiae, targeting an ultra-conserved target site in a haplosufficient essential gene (AGAP029113) required during mosquito development, which fulfils many of the criteria for the target of a population suppression gene drive. We then designed a selection regime to experimentally assess the likelihood of generation and subsequent selection of gene drive resistant mutations at its target site. We simulated, in a caged population, a scenario where the gene drive was approaching fixation, where selection for resistance is expected to be strongest. Continuous sampling of the target locus revealed that a single, restorative, in-frame nucleotide substitution was selected. Our findings show that ultra-conservation alone need not be predictive of a site that is refractory to target site resistance. Our strategy to evaluate resistance in vivo could help to validate candidate gene drive targets for their resilience to resistance and help to improve predictions of the invasion dynamics of gene drives in field populations.

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Alkilany, Alaaldin M., Stefano P. Boulos, Samuel E. Lohse, Lucas B. Thompson, and Catherine J. Murphy. "Homing Peptide-Conjugated Gold Nanorods: The Effect of Amino Acid Sequence Display on Nanorod Uptake and Cellular Proliferation." Bioconjugate Chemistry 25, no. 6 (June 3, 2014): 1162–71. http://dx.doi.org/10.1021/bc500174b.

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Costantini, Todd W., James G. Putnam, Ritsuko Sawada, Andrew Baird, William H. Loomis, Brian P. Eliceiri, Vishal Bansal, and Raul Coimbra. "Targeting the gut barrier: Identification of a homing peptide sequence for delivery into the injured intestinal epithelial cell." Surgery 146, no. 2 (August 2009): 206–12. http://dx.doi.org/10.1016/j.surg.2009.05.007.

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Bonocora, R. P., Q. Zeng, E. V. Abel, and D. A. Shub. "A homing endonuclease and the 50-nt ribosomal bypass sequence of phage T4 constitute a mobile DNA cassette." Proceedings of the National Academy of Sciences 108, no. 39 (September 19, 2011): 16351–56. http://dx.doi.org/10.1073/pnas.1107633108.

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Dybus, A., Yu H. Yu, W. Proskura, R. Lanckriet, and Ye H. Cheng. "Association of Sequence Variants in the CKM (Creatine Kinase, M-Type) Gene with Racing Performance of Homing Pigeons." Russian Journal of Genetics 56, no. 8 (August 2020): 1006–11. http://dx.doi.org/10.1134/s1022795420080025.

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Foxman, Ellen F., James J. Campbell, and Eugene C. Butcher. "Multistep Navigation and the Combinatorial Control of Leukocyte Chemotaxis." Journal of Cell Biology 139, no. 5 (December 1, 1997): 1349–60. http://dx.doi.org/10.1083/jcb.139.5.1349.

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Cells migrating within tissues may encounter multiple chemoattractant signals in complex spatial and temporal patterns. To understand leukocyte navigation in such settings, we have explored the migratory behavior of neutrophils in model scenarios where they are presented with two chemoattractant sources in various configurations. We show that, over a wide range of conditions, neutrophils can migrate “down” a local chemoattractant gradient in response to a distant gradient of a different chemoattractant. Furthermore, cells can chemotax effectively to a secondary distant agonist after migrating up a primary gradient into a saturating, nonorienting concentration of an initial attractant. Together, these observations suggest the potential for cells' step-by-step navigation from one gradient to another in complex chemoattractant fields. The importance of such sequential navigation is confirmed here in a model system in which neutrophil homing to a defined domain (a) requires serial responses to agonists presented in a defined spatial array, and (b) is a function of both the agonist combination and the sequence in which gradients are encountered. We propose a multistep model of chemoattractant-directed migration, which requires that leukocytes display multiple chemoattractant receptors for successful homing and provides for combinatorial determination of microenvironmental localization.

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Nakano, Hideki, Shigeyuki Mori, Hiromichi Yonekawa, Hideo Nariuchi, Akio Matsuzawa, and Terutaka Kakiuchi. "A Novel Mutant Gene Involved in T-Lymphocyte–Specific Homing Into Peripheral Lymphoid Organs on Mouse Chromosome 4." Blood 91, no. 8 (April 15, 1998): 2886–95. http://dx.doi.org/10.1182/blood.v91.8.2886.2886_2886_2895.

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Previously, we have shown a mutant mouse DDD/1 with T-cell–specific homing defect that is regulated by an autosomal recessive gene,plt (paucity of lymph node T cells), and seems to be caused by lymph node (LN) stromal cells. In the present study, immunohistochemical analysis showed unusual distribution of T cells in LN, Peyer's patches (PP), and spleen from plt/plt, probably due to the failure of T cells to migrate from blood into the T-cell zone in LN or PP, or into the spleen white pulp across high endothelial venule or marginal zone, respectively, based on the experiments in which labelled T cells were injected intravenously and detected in the tissues. Analysis of surface L-selectin and CD44 suggested that T cells with memory phenotype, probably from afferent lymphatics, recruit intoplt/plt LN. Linkage mapping by simple-sequence length polymorphism of genomic DNA from 190 backcross progenies produced by intercrossing with MSM/Ms, linked plt most closely with D4Mit237, and localized at 24.7 cM from cetromere on chromosome 4. We discuss the possibility that a wild-type gene on plt locus encodes a chemokine inducing T-cell–specific homing into peripheral lymphoid tissues.

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Jiang, Weiwei, Guanghui Jin, Dingyuan Ma, Feng Wang, Tong Fu, Xiao Chen, Xiwen Chen, Kunzhi Jia, Faiz M. M. T. Marikar, and Zichun Hua. "Modification of Cyclic NGR Tumor Neovasculature-Homing Motif Sequence to Human Plasminogen Kringle 5 Improves Inhibition of Tumor Growth." PLoS ONE 7, no. 5 (May 10, 2012): e37132. http://dx.doi.org/10.1371/journal.pone.0037132.

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Meckley, Trevor D., Eliezer Gurarie, James R. Miller, and C. Michael Wagner. "How fishes find the shore: evidence for orientation to bathymetry from the non-homing sea lamprey." Canadian Journal of Fisheries and Aquatic Sciences 74, no. 12 (December 2017): 2045–58. http://dx.doi.org/10.1139/cjfas-2016-0412.

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Orientation to a shoreline is the critical first step for aquatic organisms that navigate to coastal waters, estuaries, and rivers to feed or reproduce. Most studies of animal migration have focused on homing-based navigation while non-homing navigation is poorly understood. We quantified the navigation behavior of sea lamprey during their non-homing return migration to a coastline in the Laurentian Great Lakes. Acoustically tagged sea lamprey were displaced 3.3 km from shore into the center of an acoustic listening array that provided high-resolution (30 s intervals, <5 m accuracy) three-dimensional paths. Eighty-one percent of individuals arrived at the nearest coast by moving towards shallower water. A biphasic sequence of movement was documented for most individuals, a more tortuous movement closer to the bottom associated with orientation, and a faster more linear movement we associate with directed search. Sea lamprey oriented to shallow water even when that was not the shoreward direction, and did not appear to rely on memory or recognition of the nearest coast. We postulate that individuals specifically performed barokinesis, whereby individuals assessed the gradient in absolute hydrostatic pressure on the bottom and to choose a heading towards shallower water. Repeated excursions to the bottom may confirm progress, while time spent at the surface is likely associated with surface-linked olfactory cues that indicate proximity to river water entrained along the coast. This is the first evidence that suggests the shoreward gradient in hydrostatic pressure may be used during shoreward orientation, and may represent a class of sensory information not previously considered in aquatic animal navigation.

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Tedder, T. F., C. M. Isaacs, T. J. Ernst, G. D. Demetri, D. A. Adler, and C. M. Disteche. "Isolation and chromosomal localization of cDNAs encoding a novel human lymphocyte cell surface molecule, LAM-1. Homology with the mouse lymphocyte homing receptor and other human adhesion proteins." Journal of Experimental Medicine 170, no. 1 (July 1, 1989): 123–33. http://dx.doi.org/10.1084/jem.170.1.123.

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A cDNA encoding a new human lymphocyte cell surface molecule has been isolated and shown to identify a fourth member of a recently discovered family of adhesion proteins. This lymphocyte-associated molecule (LAM-1) is uniquely composed of multiple distinct domains, one domain homologous with animal lectins, one homologous with epidermal growth factor, and two short consensus repeat units similar to those found in C3/C4 binding proteins. This cDNA clone hybridized with RNAs found in B cell lines and T lymphocytes, but not with RNA from other cell types. The amino acid sequence of LAM-1 is 77% homologous with the sequence of the mouse lymphocyte homing receptor, suggesting that LAM-1 may function in human lymphocyte adhesion. The LAM-1 gene is located on chromosome 1q23-25, as is another member of this adhesion family, suggesting that this new family of proteins may be encoded by a cluster of "adhesion protein" loci.

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Staddon, Jack H., Edward M. Bryan, Dawn A. Manias, and Gary M. Dunny. "Conserved Target for Group II Intron Insertion in Relaxase Genes of Conjugative Elements of Gram-Positive Bacteria." Journal of Bacteriology 186, no. 8 (April 15, 2004): 2393–401. http://dx.doi.org/10.1128/jb.186.8.2393-2401.2004.

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ABSTRACT The lactococcal group II intron Ll.ltrB interrupts the ltrB relaxase gene within a region that encodes a conserved functional domain. Nucleotides essential for the homing of Ll.ltrB into an intronless version of ltrB are found exclusively at positions required to encode amino acids broadly conserved in a family of relaxase proteins of gram-positive bacteria. Two of these relaxase genes, pcfG from the enterococcal plasmid pCF10 and the ORF4 gene in the streptococcal conjugative transposon Tn5252, were shown to support Ll.ltrB insertion into the conserved motif at precisely the site predicted by sequence homology with ltrB. Insertion occurred through a mechanism indistinguishable from retrohoming. Splicing and retention of conjugative function was demonstrated for pCF10 derivatives containing intron insertions. Ll.ltrB targeting of a conserved motif of a conjugative element suggests a mechanism for group II intron dispersal among bacteria. Additional support for this mechanism comes from sequence analysis of the insertion sites of the E.c.I4 family of bacterial group II introns.

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Ligat, Gaëtan, Anthony Couvreux, Raphaël Cazal, Sophie Alain, and Sébastien Hantz. "Highlighting of a LAGLIDADG and a Zing Finger Motifs Located in the pUL56 Sequence Crucial for HCMV Replication." Viruses 11, no. 12 (November 26, 2019): 1093. http://dx.doi.org/10.3390/v11121093.

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The human cytomegalovirus (HCMV) terminase complex is part of DNA-packaging machinery that delivers a unit-length genome into a procapsid. Sequence comparison of herpesvirus homologs allowed us to identify a potential LATLNDIERFL and zinc finger pattern in N-terminal part of pUL56. Recombinant viruses were generated with specific serine or alanine substitutions in these putative patterns. We identified a LATLNDIERFL pattern characteristic of LAGLIDADG homing endonucleases and a metal-binding pattern involving the cysteine and histidine residues C191-X2-C194-X22-C217-X-H219 (CCCH) close to the region conferring letermovir resistance. These patterns are crucial for viral replication, suggesting that they are essential for pUL56 structure and function. Thus, these patterns represent potential targets for the development of new antivirals such as small molecules or peptides and may allow to better understand the letermovir mechanism of action.

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Journal articles on the topic 'Homing sequence'

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