The vibriophage-encoded inhibitor OrbA abrogates BREX-mediated defense through the ATPase BrxC
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Abstract
Bacteria and phages are locked in a co-evolutionary arms race where each entity evolves mechanisms to restrict the proliferation of the other. Phage-encoded defense inhibitors have proven powerful tools to interrogate how defense systems function. A relatively common defense system is BREX (bacteriophage exclusion); however, how BREX functions to restrict phage infection remains poorly understood. A BREX system encoded by the s ulfametho x azole and t rimethoprim (SXT) integrative and conjugative element, Vch Ind5, was recently identified in Vibrio cholerae , the causative agent of the diarrheal disease cholera. The lytic phage ICP1 ( I nternational Centre for Diarrhoeal Disease Research, Bangladesh c holera p hage 1 ) that co-circulates with V. cholerae encodes the BREX-inhibitor OrbA, but how OrbA inhibits BREX is unclear. Here, we determine that OrbA inhibits BREX using a unique mechanism from known BREX inhibitors by directly binding to the BREX component BrxC. BrxC has a functional ATPase domain that, when mutated, not only disrupts BrxC function but also alters how BrxC multimerizes. Furthermore, we find that OrbA binding disrupts BrxC-BrxC interactions. We determine that OrbA cannot bind BrxC encoded by the distantly related BREX system encoded by the aSXT Vch Ban9, and thus fails to inhibit this BREX system that also circulates in epidemic V. cholerae . Lastly, we find that homologs of the Vch Ind5 BrxC are more diverse than the homologs of the Vch Ban9 BrxC. These data provide new insight into the function of the BrxC ATPase and highlight how phage-encoded inhibitors can disrupt phage defense systems using different mechanisms. IMPORTANCE: With renewed interest in phage therapy to combat antibiotic-resistant pathogens, understanding the mechanisms bacteria use to defend themselves against phages and the counter-strategies phages evolve to inhibit defenses is paramount. Bacteriophage exclusion (BREX) is a common defense system with few known inhibitors. Here, we probe how the vibriophage-encoded inhibitor OrbA inhibits the BREX system of Vibrio cholerae , the causative agent of the diarrheal disease cholera. By interrogating OrbA function, we have begun to understand the importance and function of a BREX component. Our results demonstrate the importance of identifying inhibitors against defense systems, as they are powerful tools for dissecting defense activity and can inform strategies to increase the efficacy of some phage therapies.
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Cites
MAFFT Multiple Sequence Alignment Software Version 7: Improvements in Performance and Usability
Katoh, K., & Standley, D. M. (2013) · Molecular Biology and Evolution · doi:10.1093/molbev/mst010 · Cited by 46,209 · see citing works
Highly accurate protein structure prediction with AlphaFold
Jumper, J., Evans, R., Pritzel, A., Green, T., Figurnov, M., Ronneberger, O., Tunyasuvunakool, K., Bates, R., Žídek, A., Potapenko, A., et al. (2021) · Nature · doi:10.1038/s41586-021-03819-2 · Cited by 43,764 · see citing works
Cd-hit: Accelerated for clustering the next-generation sequencing data
Fu, L., Niu, B., Zhu, Z., Wu, S., & Li, W. (2012) · Bioinformatics · doi:10.1093/bioinformatics/bts565 · Cited by 11,175 · see citing works
Interactive Tree Of Life (iTOL) v5: an online tool for phylogenetic tree display and annotation
Letunic, I., & Bork, P. (2021) · Nucleic Acids Res. · doi:10.1093/nar/gkab301 · Cited by 9,899 · see citing works
The Phyre2 web portal for protein modeling, prediction and analysis
Kelley, L. A., Mezulis, S., Yates, C. M., Wass, M. N., & Sternberg, M. J. E. (2015) · Nature Protocols · doi:10.1038/nprot.2015.053 · Cited by 9,652 · see citing works
ColabFold - Making protein folding accessible to all
Mirdita, M., Schütze, K., Moriwaki, Y., Heo, L., Ovchinnikov, S., & Steinegger, M. (2021) · doi:10.1101/2021.08.15.456425 · Cited by 9,391 · see citing works
Pfam: The protein families database in 2021
Mistry, J., Chuguransky, S., Williams, L., Qureshi, M., Salazar, G. A., Sonnhammer, E. L. L., Tosatto, S. C. E., Paladin, L., Raj, S., Richardson, L. J., et al. (2021) · Nucleic Acids Research · doi:10.1093/nar/gkaa913 · Cited by 7,452 · see citing works
UCSF ChimeraX : Tools for structure building and analysis
Meng, E. C., Goddard, T. D., Pettersen, E. F., Couch, G. S., Pearson, Z., Morris, J. H., & Ferrin, T. E. (2023) · Protein Science · doi:10.1002/pro.4792 · Cited by 4,575 · see citing works
A Completely Reimplemented MPI Bioinformatics Toolkit with a New HHpred Server at its Core
Zimmermann, L., Stephens, A., Nam, S.-Z., Rau, D., Kübler, J., Lozajic, M., Gabler, F., Söding, J., Lupas, A. N., & Alva, V. (2018) · Journal of Molecular Biology · doi:10.1016/j.jmb.2017.12.007 · Cited by 2,522 · see citing works
Bacteriophage resistance mechanisms
Labrie, S. J., Samson, J. E., & Moineau, S. (2010) · Nature Reviews Microbiology · doi:10.1038/nrmicro2315 · Cited by 2,405 · see citing works
Evolutionary classification of CRISPR–Cas systems: a burst of class 2 and derived variants
Makarova, K. S., Wolf, Y. I., Iranzo, J., Shmakov, S., Alkhnbashi, O. S., Brouns, S. J. J., Charpentier, E., Cheng, D. R., Haft, D. H., Horvath, P., et al. (2019) · Nature Reviews Microbiology · doi:10.1038/s41579-019-0299-x · Cited by 2,326 · see citing works
A bacterial two-hybrid system based on a reconstituted signal transduction pathway
Karimova, G., Pidoux, J., Ullmann, A., & Ladant, D. (1998) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.95.10.5752 · Cited by 1,664 · see citing works
The DNA methyltransferase family: a versatile toolkit for epigenetic regulation
Lyko, F. (2017) · Nature Reviews Genetics · doi:10.1038/nrg.2017.80 · Cited by 1,475 · see citing works
Systematic discovery of antiphage defense systems in the microbial pangenome
Doron, S., Melamed, S., Ofir, G., Leavitt, A., Lopatina, A., Keren, M., Amitai, G., & Sorek, R. (2018) · Science · doi:10.1126/science.aar4120 · Cited by 1,190 · see citing works
AAA+ superfamily ATPases: common structure–diverse function
Ogura, T., & Wilkinson, A. J. (2001) · Genes to Cells · doi:10.1046/j.1365-2443.2001.00447.x · Cited by 958 · see citing works
Protein Sequence Analysis Using the MPI Bioinformatics Toolkit
Gabler, F., Nam, S., Till, S., Mirdita, M., Steinegger, M., Söding, J., Lupas, A. N., & Alva, V. (2020) · Current Protocols in Bioinformatics · doi:10.1002/cpbi.108 · Cited by 831 · see citing works
Systematic and quantitative view of the antiviral arsenal of prokaryotes
Tesson, F., Hervé, A., Mordret, E., Touchon, M., d’Humières, C., Cury, J., & Bernheim, A. G. (2022) · Nature Communications · doi:10.1038/s41467-022-30269-9 · Cited by 772 · see citing works
RESTRICTION AND MODIFICATION SYSTEMS
Wilson, G. G., & Murray, N. E. (1991) · Annual Review of Genetics · doi:10.1146/annurev.ge.25.120191.003101 · Cited by 714 · see citing works
CRISPR/Cas System and Its Role in Phage-Bacteria Interactions
Deveau, H., Garneau, J. E., & Moineau, S. (2010) · Annual Review of Microbiology · doi:10.1146/annurev.micro.112408.134123 · Cited by 624 · see citing works
Diverse enzymatic activities mediate antiviral immunity in prokaryotes
Gao, L. A., Altae-Tran, H., Böhning, F., Makarova, K. S., Segel, M., Schmid-Burgk, J. L., Koob, J. G., Wolf, Y. I., Koonin, E. V., & Zhang, F. (2020) · Science · doi:10.1126/science.aba0372 · Cited by 612 · see citing works
The biology of restriction and anti-restriction
Tock, M. R., & Dryden, D. T. F. (2005) · Current Opinion in Microbiology · doi:10.1016/j.mib.2005.06.003 · Cited by 593 · see citing works
BREX is a novel phage resistance system widespread in microbial genomes
Goldfarb, T., Sberro, H., Weinstock, E., Cohen, O., Doron, S., Charpak‐Amikam, Y., Afik, S., Ofir, G., & Sorek, R. (2014) · The EMBO Journal · doi:10.15252/embj.201489455 · Cited by 501 · see citing works
An expanded arsenal of immune systems that protect bacteria from phages
Millman, A., Melamed, S., Leavitt, A., Doron, S., Bernheim, A., Hör, J., Garb, J., Bechon, N., Brandis, A., Lopatina, A., et al. (2022) · Cell Host & Microbe · doi:10.1016/j.chom.2022.09.017 · Cited by 428 · see citing works
Xu, Y., & Li, Z. (2020) · Computational and Structural Biotechnology Journal · doi:10.1016/j.csbj.2020.08.031 · Cited by 424 · see citing works
Vassallo, C. N., Doering, C. R., Littlehale, M. L., Teodoro, G. I. C., & Laub, M. T. (2022) · Nature Microbiology · doi:10.1038/s41564-022-01219-4 · Cited by 304 · see citing works
Comparative ICE Genomics: Insights into the Evolution of the SXT/R391 Family of ICEs
Wozniak, R. A. F., Fouts, D. E., Spagnoletti, M., Colombo, M. M., Ceccarelli, D., Garriss, G., Déry, C., Burrus, V., & Waldor, M. K. (2009) · PLoS Genetics · doi:10.1371/journal.pgen.1000786 · Cited by 282 · see citing works
Transcription in Living Cells: Molecular Mechanisms of Bursting
Rodriguez, J., & Larson, D. R. (2020) · Annual Review of Biochemistry · doi:10.1146/annurev-biochem-011520-105250 · Cited by 224 · see citing works
AAA+ ATPases: Achieving Diversity of Function with Conserved Machinery
White, S. R., & Lauring, B. P. (2007) · Traffic · doi:10.1111/j.1600-0854.2007.00642.x · Cited by 221 · see citing works
Multiplex genome editing by natural transformation
Dalia, A. B., McDonough, E., & Camilli, A. (2014) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1406478111 · Cited by 207 · see citing works
Structure of Ocr from Bacteriophage T7, a Protein that Mimics B-Form DNA
Walkinshaw, M. D., Taylor, P., Sturrock, S. S., Atanasiu, C., Berge, T., Henderson, R. M., Edwardson, J. M., & Dryden, D. T. F. (2002) · Molecular Cell · doi:10.1016/s1097-2765(02)00435-5 · Cited by 189 · see citing works
Structural biology of CRISPR–Cas immunity and genome editing enzymes
Wang, J. Y., Pausch, P., & Doudna, J. A. (2022) · Nature Reviews Microbiology · doi:10.1038/s41579-022-00739-4 · Cited by 186 · see citing works
Anti-CRISPRs: Protein Inhibitors of CRISPR-Cas Systems
Davidson, A. R., Lu, W., Stanley, S. Y., Wang, J., Mejdani, M., Trost, C. N., Hicks, B. T., Lee, J., & Sontheimer, E. J. (2020) · Annual Review of Biochemistry · doi:10.1146/annurev-biochem-011420-111224 · Cited by 167 · see citing works
Temporal shifts in antibiotic resistance elements govern phage-pathogen conflicts
LeGault, K. N., Hays, S. G., Angermeyer, A., McKitterick, A. C., Johura, F., Sultana, M., Ahmed, T., Alam, M., & Seed, K. D. (2021) · Science · doi:10.1126/science.abg2166 · Cited by 150 · see citing works
Self-citationCrystal structure of the eukaryotic origin recognition complex
Bleichert, F., Botchan, M. R., & Berger, J. M. (2015) · Nature · doi:10.1038/nature14239 · Cited by 139 · see citing works
Cianfrocco, M. A., Wong-Barnum, M., Youn, C., Wagner, R., & Leschziner, A. E. (2017) · Practice and Experience in Advanced Research Computing · doi:10.1145/3093338.3093390 · Cited by 129 · see citing works
SAMase gene of bacteriophage T3 is responsible for overcoming host restriction
Studier, F. W., & Movva, N. R. (1976) · Journal of Virology · doi:10.1128/jvi.19.1.136-145.1976 · Cited by 127 · see citing works
Gordeeva, J., Morozova, N. E., Sierro, N., Isaev, A. B., Šinkūnas, T., Tsvetkova, K., Matlashov, M. E., Truncaitė, L., Morgan, R., Ivanov, N. V., et al. (2018) · Nucleic Acids Research · doi:10.1093/nar/gky1125 · Cited by 110 · see citing works
Structure-based functional mechanisms and biotechnology applications of anti-CRISPR proteins
Jia, N., & Patel, D. J. (2021) · Nature Reviews Molecular Cell Biology · doi:10.1038/s41580-021-00371-9 · Cited by 108 · see citing works
Phage T7 DNA mimic protein Ocr is a potent inhibitor of BREX defence
Isaev, A. B., Drobiazko, A., Sierro, N., Gordeeva, J., Yosef, I., Qimron, U., Ivanov, N. V., & Severinov, K. (2020) · Nucleic Acids Research · doi:10.1093/nar/gkaa290 · Cited by 106 · see citing works
The growing repertoire of phage anti-defence systems
Murtazalieva, K., Mu, A., Petrovskaya, A. V., & Finn, R. D. (2024) · Trends in Microbiology · doi:10.1016/j.tim.2024.05.005 · Cited by 99 · see citing works
Picton, D. M., Luyten, Y. A., Morgan, R., Nelson, A., Smith, D., Dryden, D. T. F., Hinton, J. C. D., & Blower, T. R. (2021) · Nucleic Acids Research · doi:10.1093/nar/gkab906 · Cited by 98 · see citing works
Bacteriophages suppress CRISPR–Cas immunity using RNA-based anti-CRISPRs
Camara-Wilpert, S., Mayo-Muñoz, D., Russel, J., Fagerlund, R. D., Madsen, J. S., Fineran, P. C., Sørensen, S. J., & Pinilla‐Redondo, R. (2023) · Nature · doi:10.1038/s41586-023-06612-5 · Cited by 94 · see citing works
Bandyopadhyay, P. K., Studier, F. W., Hamilton, D. L., & Yuan, R. T. (1985) · Journal of Molecular Biology · doi:10.1016/0022-2836(85)90242-6 · Cited by 84 · see citing works
ATP bound to the origin recognition complex is important for preRC formation
Klemm, R. D., & Bell, S. P. (2001) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.131006898 · Cited by 83 · see citing works
Specificity and Function of Archaeal DNA Replication Initiator Proteins
Samson, R. Y., Xu, Y., Gadelha, C., Stone, T. A., Faqiri, J. N., Li, D., Qin, N., Pu, F., Liang, Y. X., She, Q., et al. (2013) · Cell Reports · doi:10.1016/j.celrep.2013.01.002 · Cited by 83 · see citing works
Structural Mechanisms for Replicating DNA in Eukaryotes
Attali, I., Botchan, M. R., & Berger, J. M. (2021) · Annual Review of Biochemistry · doi:10.1146/annurev-biochem-090120-125407 · Cited by 62 · see citing works
Picton, D. M., Harling-Lee, J. D., Duffner, S. J., Went, S. C., Morgan, R., Hinton, J. C. D., & Blower, T. R. (2022) · Nucleic Acids Research · doi:10.1093/nar/gkac334 · Cited by 55 · see citing works
Greci, M. D., & Bell, S. D. (2020) · Annual Review of Microbiology · doi:10.1146/annurev-micro-020518-115443 · Cited by 53 · see citing works
Mechanism of Archaeal MCM Helicase Recruitment to DNA Replication Origins
Samson, R. Y., Abeyrathne, P. D., & Bell, S. D. (2015) · Molecular Cell · doi:10.1016/j.molcel.2015.12.005 · Cited by 49 · see citing works
Barth, Z. K., Silvas, T. V., Angermeyer, A., & Seed, K. D. (2019) · Nucleic Acids Research · doi:10.1093/nar/gkz1005 · Cited by 48 · see citing works
Self-citationExploring the DNA mimicry of the Ocr protein of phage T7
Roberts, G. A., Stephanou, A. S., Kanwar, N., Dawson, A. J., Cooper, L. P., Chen, K., NUTLEY, M. A., Cooper, A., Blakely, G. W., & Dryden, D. T. F. (2012) · Nucleic Acids Research · doi:10.1093/nar/gks516 · Cited by 46 · see citing works
Luyten, Y. A., Hausman, D., Young, J. C., Doyle, L., Higashi, K. M., Ubilla‐Rodriguez, N. C., Lambert, A. R., Arroyo, C. S., Forsberg, K. J., Morgan, R., et al. (2022) · Nucleic Acids Research · doi:10.1093/nar/gkac311 · Cited by 42 · see citing works
A phage parasite deploys a nicking nuclease effector to inhibit viral host replication
LeGault, K. N., Barth, Z. K., DePaola, P., & Seed, K. D. (2022) · Nucleic Acids Research · doi:10.1093/nar/gkac002 · Cited by 40 · see citing works
Self-citationAndriianov, A., Trigüis, S., Drobiazko, A., Sierro, N., Ivanov, N. V., Selmer, M., Severinov, K., & Isaev, A. B. (2023) · Cell Reports · doi:10.1016/j.celrep.2023.112972 · Cited by 33 · see citing works
Zaworski, J., Dagva, O., Brandt, J., Baum, C., Ettwiller, L. M., Fomenkov, A. I., & Raleigh, E. A. (2022) · PLoS Genetics · doi:10.1371/journal.pgen.1009943 · Cited by 20 · see citing works
Shen, B. W., Doyle, L., Werther, R. A., Westburg, A. A., Bies, D. P., Walter, S. I., Luyten, Y. A., Morgan, R., Stoddard, B. L., & Kaiser, B. K. (2023) · Nucleic Acids Research · doi:10.1093/nar/gkad083 · Cited by 20 · see citing works
Crystal structure of the BREX phage defence protein BrxA
Beck, I. N., Picton, D. M., & Blower, T. R. (2022) · Current Research in Structural Biology · doi:10.1016/j.crstbi.2022.06.001 · Cited by 19 · see citing works
COSMIC2: A global resource for structure prediction and structural analysis
Cianfrocco, M. A. (2024) · Biophysical Journal · doi:10.1016/j.bpj.2023.11.2036 · Cited by 6 · see citing works
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- Authors
- Oshiro, R. T., Dunham, D. T., & Seed, K. D.
- Affiliations
- University of California, Berkeley (US)
- Corresponding author
- Seed, Kimberley D.
- Venue
- Journal of Bacteriology
- Publisher
- American Society for Microbiology
- Published
- 2024-11-21
- Volume
- 206
- Issue
- 11
- Pages
- e0020624-e0020624
- ISSN
- 0021-9193 (ISSN-L)
- 1098-5530
- PMC
- PMC11580459
- OpenAlex
- W4403406635
- Cited by
- 15
- References
- 58
- Citations by year
- 2026: 8 · 2025: 7
- FWCI
- 4.10
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- Locations
- Journal of Bacteriology (publishedVersion, cc-by)
- bioRxiv (Cold Spring Harbor Laboratory) (acceptedVersion, cc-by-nd)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- eScholarship (California Digital Library) (submittedVersion, cc-by)
- PubMed Central (submittedVersion)
- Funders
- HHS | NIH | National Institute of Allergy and Infectious Diseases (R01AI153303)
- Topics
- Physical Sciences › Environmental Science › Ecology › Bacteriophages and microbial interactions
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Bacterial Genetics and Biotechnology
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › CRISPR and Genetic Engineering
- Keywords
- Vibrio cholerae, phage-bacteria coevolution, integrative and conjugative elements, protein-protein interaction, phage therapy, antibiotic resistance, cholera
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