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Mobley HLT, Anderson MT, Moricz BS, Severin GB, Holmes CL, Ottosen EN, Eichler T, Gupta S, Paudel S, Sinha R, Mason S, Himpsl SD, Brown AN, Gaca M, Kiser CM, Clarke TH, Fouts DE, DiRita VJ, Bachman MA. Fitness factor genes conserved within the multi-species core genome of Gram-negative Enterobacterales species contribute to bacteremia pathogenesis. PLoS Pathog 2024; 20:e1012495. [PMID: 39178317 PMCID: PMC11376589 DOI: 10.1371/journal.ppat.1012495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 09/05/2024] [Accepted: 08/09/2024] [Indexed: 08/25/2024] Open
Abstract
There is a critical gap in knowledge about how Gram-negative bacterial pathogens, using survival strategies developed for other niches, cause lethal bacteremia. Facultative anaerobic species of the Enterobacterales order are the most common cause of Gram-negative bacteremia, including Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Citrobacter freundii, and Enterobacter hormaechei. Bacteremia often leads to sepsis, a life-threatening organ dysfunction resulting from unregulated immune responses to infection. Despite a lack of specialization for this host environment, Gram-negative pathogens cause nearly half of bacteremia cases annually. Based on our existing Tn-Seq fitness factor data from a murine model of bacteremia combined with comparative genomics of the five Enterobacterales species above, we prioritized 18 conserved fitness genes or operons for further characterization. Mutants were constructed for all genes in all five species. Each mutant was used to cochallenge C57BL/6 mice via tail vein injection along with each respective wild-type strain to determine competitive indices for each fitness gene. Five fitness factor genes, when mutated, attenuated mutants in four or five species in the spleen and liver (tatC, ruvA, gmhB, wzxE, arcA). Five additional fitness factor genes or operons were validated as outcompeted by wild-type in three, four, or five bacterial species in the spleen (xerC, prc, apaGH, atpG, aroC). Overall, 17 of 18 fitness factor mutants were attenuated in at least one species in the spleen or liver. Together, these findings allow for the development of a model of bacteremia pathogenesis that may include future targets of therapy against bloodstream infections.
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Affiliation(s)
- Harry L T Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Mark T Anderson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Bridget S Moricz
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Geoffrey B Severin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Caitlyn L Holmes
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Elizabeth N Ottosen
- Department of Microbiology and Molecular Genetics, Michigan State University College of Natural Sciences, East Lansing, Michigan, United States of America
| | - Tad Eichler
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Surbhi Gupta
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Santosh Paudel
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Ritam Sinha
- Department of Microbiology and Molecular Genetics, Michigan State University College of Natural Sciences, East Lansing, Michigan, United States of America
| | - Sophia Mason
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Stephanie D Himpsl
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Aric N Brown
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Margaret Gaca
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Christina M Kiser
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Thomas H Clarke
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Derrick E Fouts
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Victor J DiRita
- Department of Microbiology and Molecular Genetics, Michigan State University College of Natural Sciences, East Lansing, Michigan, United States of America
| | - Michael A Bachman
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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Kovacs CJ, Antonacci A, Graham A, Jessup F, Rankin W, Brasko B, Maguire F, Washington MA, Kua SC, Burpo FJ, Barnhill JC. Comparing Methods to Genetically Engineer Bacteriophage and Increase Host Range. Mil Med 2024; 189:e1488-e1496. [PMID: 38780999 DOI: 10.1093/milmed/usae226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 11/15/2023] [Accepted: 04/30/2024] [Indexed: 05/25/2024] Open
Abstract
INTRODUCTION Antibacterial resistance is an emerging problem in military medicine. Disruptions to the health care systems in war-torn countries that result from ongoing conflict can potentially exacerbate this problem and increase the risk to U.S. forces in the deployed environment. Therefore, novel therapies are needed to mitigate the impact of these potentially devastating infections on military operations. Bacteriophages are viruses that infect and kill bacteria. They can be delivered as therapeutic agents and offer a promising alternative to traditional antibiotic chemotherapy. There are several potential benefits to their use, including high specificity and comparative ease of use in the field setting. However, the process of engineering phages for military medical applications can be a laborious and time-consuming endeavor. This review examines available techniques and compares their efficacy. MATERIALS AND METHODS This review evaluates the scientific literature on the development and application of four methods of bacteriophage genome engineering and their consideration in the context of military applications. Preffered Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed for a systematic review of available literature that met criteria for analysis and inclusion. The research completed for this review article originated from the United States Military Academy's library "Scout" search engine, which compiles results from 254 available databases (including PubMed, Google Scholar, and SciFinder). Particular attention was focused on identifying useful mechanistic insight into the nature of the engineering technique, the ease of use, and the applicability of the technique to countering the problem of antimicrobial resistance in the military setting. RESULTS A total of 52 studies were identified that met inclusion criteria following PRISMA guidelines. The bioengineering techniques analyzed included homologous recombination (12 articles), in vivo recombineering (9 articles), bacteriophage recombineering of electroporated DNA (7 articles), and the CRISPR-Cas system (10 articles). Rates of success and fidelity varied across each platform, and comparative benefits and drawbacks are considered. CONCLUSIONS Each of the phage engineering techniques addressed herein varies in amount of effort and overall success rate. CRISPR-Cas-facilitated modification of phage genomes presents a highly efficient method that does not require a lengthy purification and screening process. It therefore appears to be the method best suited for military medical applications.
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Affiliation(s)
- Christopher J Kovacs
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
- Defense Threat Reduction Agency, Fort Belvoir, VA 22060, USA
| | - Alessia Antonacci
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
| | - Abigail Graham
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
| | - Faye Jessup
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
| | - William Rankin
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
| | - Brianna Brasko
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
| | - Fiona Maguire
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
| | - Michael A Washington
- Department of Clinical Investigation, Dwight D. Eisenhower Army Medical Center, Fort Gordon, GA 30905, USA
| | - Siang C Kua
- Department of Clinical Investigation, Dwight D. Eisenhower Army Medical Center, Fort Gordon, GA 30905, USA
| | - F John Burpo
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
| | - Jason C Barnhill
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
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3
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Liljegren MM, Gama JA, Johnsen PJ, Harms K. The recombination initiation functions DprA and RecFOR suppress microindel mutations in Acinetobacter baylyi ADP1. Mol Microbiol 2024; 122:1-10. [PMID: 38760330 DOI: 10.1111/mmi.15277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 04/24/2024] [Accepted: 04/26/2024] [Indexed: 05/19/2024]
Abstract
Short-Patch Double Illegitimate Recombination (SPDIR) has been recently identified as a rare mutation mechanism. During SPDIR, ectopic DNA single-strands anneal with genomic DNA at microhomologies and get integrated during DNA replication, presumably acting as primers for Okazaki fragments. The resulting microindel mutations are highly variable in size and sequence. In the soil bacterium Acinetobacter baylyi, SPDIR is tightly controlled by genome maintenance functions including RecA. It is thought that RecA scavenges DNA single-strands and renders them unable to anneal. To further elucidate the role of RecA in this process, we investigate the roles of the upstream functions DprA, RecFOR, and RecBCD, all of which load DNA single-strands with RecA. Here we show that all three functions suppress SPDIR mutations in the wildtype to levels below the detection limit. While SPDIR mutations are slightly elevated in the absence of DprA, they are strongly increased in the absence of both DprA and RecA. This SPDIR-avoiding function of DprA is not related to its role in natural transformation. These results suggest a function for DprA in combination with RecA to avoid potentially harmful microindel mutations, and offer an explanation for the ubiquity of dprA in the genomes of naturally non-transformable bacteria.
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Affiliation(s)
- Mikkel M Liljegren
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
| | - João A Gama
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Madrid, Spain
| | - Pål J Johnsen
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
| | - Klaus Harms
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
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Royzenblat SK, Freddolino L. Spatio-temporal organization of the E. coli chromosome from base to cellular length scales. EcoSal Plus 2024:eesp00012022. [PMID: 38864557 DOI: 10.1128/ecosalplus.esp-0001-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 04/17/2024] [Indexed: 06/13/2024]
Abstract
Escherichia coli has been a vital model organism for studying chromosomal structure, thanks, in part, to its small and circular genome (4.6 million base pairs) and well-characterized biochemical pathways. Over the last several decades, we have made considerable progress in understanding the intricacies of the structure and subsequent function of the E. coli nucleoid. At the smallest scale, DNA, with no physical constraints, takes on a shape reminiscent of a randomly twisted cable, forming mostly random coils but partly affected by its stiffness. This ball-of-spaghetti-like shape forms a structure several times too large to fit into the cell. Once the physiological constraints of the cell are added, the DNA takes on overtwisted (negatively supercoiled) structures, which are shaped by an intricate interplay of many proteins carrying out essential biological processes. At shorter length scales (up to about 1 kb), nucleoid-associated proteins organize and condense the chromosome by inducing loops, bends, and forming bridges. Zooming out further and including cellular processes, topological domains are formed, which are flanked by supercoiling barriers. At the megabase-scale both large, highly self-interacting regions (macrodomains) and strong contacts between distant but co-regulated genes have been observed. At the largest scale, the nucleoid forms a helical ellipsoid. In this review, we will explore the history and recent advances that pave the way for a better understanding of E. coli chromosome organization and structure, discussing the cellular processes that drive changes in DNA shape, and what contributes to compaction and formation of dynamic structures, and in turn how bacterial chromatin affects key processes such as transcription and replication.
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Affiliation(s)
- Sonya K Royzenblat
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Lydia Freddolino
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Computational Medicine & Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Ribeiro ALJL, Pérez-Arnaiz P, Sánchez-Costa M, Pérez L, Almendros M, van Vliet L, Gielen F, Lim J, Charnock S, Hollfelder F, González-Pastor JE, Berenguer J, Hidalgo A. Thermostable in vitro transcription-translation compatible with microfluidic droplets. Microb Cell Fact 2024; 23:169. [PMID: 38858677 PMCID: PMC11165818 DOI: 10.1186/s12934-024-02440-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 05/25/2024] [Indexed: 06/12/2024] Open
Abstract
BACKGROUND In vitro expression involves the utilization of the cellular transcription and translation machinery in an acellular context to produce one or more proteins of interest and has found widespread application in synthetic biology and in pharmaceutical biomanufacturing. Most in vitro expression systems available are active at moderate temperatures, but to screen large libraries of natural or artificial genetic diversity for highly thermostable enzymes or enzyme variants, it is instrumental to enable protein synthesis at high temperatures. OBJECTIVES Develop an in vitro expression system operating at high temperatures compatible with enzymatic assays and with technologies that enable ultrahigh-throughput protein expression in reduced volumes, such as microfluidic water-in-oil (w/o) droplets. RESULTS We produced cell-free extracts from Thermus thermophilus for in vitro translation including thermostable enzymatic cascades for energy regeneration and a moderately thermostable RNA polymerase for transcription, which ultimately limited the temperature of protein synthesis. The yield was comparable or superior to other thermostable in vitro expression systems, while the preparation procedure is much simpler and can be suited to different Thermus thermophilus strains. Furthermore, these extracts have enabled in vitro expression in microfluidic droplets at high temperatures for the first time. CONCLUSIONS Cell-free extracts from Thermus thermophilus represent a simpler alternative to heavily optimized or pure component thermostable in vitro expression systems. Moreover, due to their compatibility with droplet microfluidics and enzyme assays at high temperatures, the reported system represents a convenient gateway for enzyme screening at higher temperatures with ultrahigh-throughput.
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Grants
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- BIO-2013-44963-R, RED2022-134755-T, CEX2021-001154-S Ministerio de Ciencia e Innovación
- BIO-2013-44963-R, RED2022-134755-T, CEX2021-001154-S Ministerio de Ciencia e Innovación
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Affiliation(s)
- Ana L J L Ribeiro
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Patricia Pérez-Arnaiz
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Mercedes Sánchez-Costa
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Lara Pérez
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Marcos Almendros
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Liisa van Vliet
- Departament of Biochemistry, Cambridge University, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
- DropTech Ltd, 91 Canterbury Court, Cambridge, CB4 3QU, UK
| | - Fabrice Gielen
- DropTech Ltd, 91 Canterbury Court, Cambridge, CB4 3QU, UK
- Living Systems Institute, Faculty of Health and Life Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Department of Physics and Astronomy, Faculty of Environment, Science and Economy, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - Jesmine Lim
- Prozomix Ltd, Building 4, West End Ind. Estate, Haltwhistle, Northumberland, NE49 9HA, UK
| | - Simon Charnock
- Prozomix Ltd, Building 4, West End Ind. Estate, Haltwhistle, Northumberland, NE49 9HA, UK
| | - Florian Hollfelder
- Departament of Biochemistry, Cambridge University, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - J Eduardo González-Pastor
- Centro de Astrobiología (CAB), CSIC-INTA, Ctra de Torrejón a Ajalvir, Km 4, 28850, Torrejón de Ardoz, Spain
| | - José Berenguer
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Aurelio Hidalgo
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain.
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain.
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain.
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Skutel M, Yanovskaya D, Demkina A, Shenfeld A, Musharova O, Severinov K, Isaev A. RecA-dependent or independent recombination of plasmid DNA generates a conflict with the host EcoKI immunity by launching restriction alleviation. Nucleic Acids Res 2024; 52:5195-5208. [PMID: 38567730 PMCID: PMC11109961 DOI: 10.1093/nar/gkae243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 03/17/2024] [Accepted: 03/22/2024] [Indexed: 05/23/2024] Open
Abstract
Bacterial defence systems are tightly regulated to avoid autoimmunity. In Type I restriction-modification (R-M) systems, a specific mechanism called restriction alleviation (RA) controls the activity of the restriction module. In the case of the Escherichia coli Type I R-M system EcoKI, RA proceeds through ClpXP-mediated proteolysis of restriction complexes bound to non-methylated sites that appear after replication or reparation of host DNA. Here, we show that RA is also induced in the presence of plasmids carrying EcoKI recognition sites, a phenomenon we refer to as plasmid-induced RA. Further, we show that the anti-restriction behavior of plasmid-borne non-conjugative transposons such as Tn5053, previously attributed to their ardD loci, is due to plasmid-induced RA. Plasmids carrying both EcoKI and Chi sites induce RA in RecA- and RecBCD-dependent manner. However, inactivation of both RecA and RecBCD restores RA, indicating that there exists an alternative, RecA-independent, homologous recombination pathway that is blocked in the presence of RecBCD. Indeed, plasmid-induced RA in a RecBCD-deficient background does not depend on the presence of Chi sites. We propose that processing of random dsDNA breaks in plasmid DNA via homologous recombination generates non-methylated EcoKI sites, which attract EcoKI restriction complexes channeling them for ClpXP-mediated proteolysis.
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Affiliation(s)
- Mikhail Skutel
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Daria Yanovskaya
- Skolkovo Institute of Science and Technology, Moscow, Russia
- Moscow Institute of Physics and Technology, Moscow, Russia
| | - Alina Demkina
- Skolkovo Institute of Science and Technology, Moscow, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
| | | | - Olga Musharova
- Skolkovo Institute of Science and Technology, Moscow, Russia
- Institute of Molecular Genetics, National Research Center Kurchatov Institute, Moscow, Russia
| | - Konstantin Severinov
- Waksman Institute of Microbiology, Piscataway, USA
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Artem Isaev
- Skolkovo Institute of Science and Technology, Moscow, Russia
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Tang J, Herzfeld AM, Leon G, Brynildsen MP. Differential impacts of DNA repair machinery on fluoroquinolone persisters with different chromosome abundances. mBio 2024; 15:e0037424. [PMID: 38564687 PMCID: PMC11077951 DOI: 10.1128/mbio.00374-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 03/06/2024] [Indexed: 04/04/2024] Open
Abstract
DNA repair machinery has been found to be indispensable for fluoroquinolone (FQ) persistence of Escherichia coli. Previously, we found that cells harboring two copies of the chromosome (2Chr) in stationary-phase cultures were more likely to yield FQ persisters than those with one copy of the chromosome (1Chr). Furthermore, we found that RecA and RecB were required to observe that difference, and that loss of either more significantly impacted 2Chr persisters than 1Chr persisters. To better understand the survival mechanisms of persisters with different chromosome abundances, we examined their dependencies on different DNA repair proteins. Here, we show that lexA3 and ∆recN negatively impact the abundances of 2Chr persisters to FQs, without significant impacts on 1Chr persisters. In comparison, ∆xseA, ∆xseB, and ∆uvrD preferentially depress 1Chr persistence to levels that were near the limit of detection. Collectively, these data show that the DNA repair mechanisms used by persisters vary based on chromosome number, and suggest that efforts to eradicate FQ persisters will likely have to take heterogeneity in single-cell chromosome abundance into consideration. IMPORTANCE Persisters are rare phenotypic variants in isogenic populations that survive antibiotic treatments that kill the other cells present. Evidence has accumulated that supports a role for persisters in chronic and recurrent infections. Here, we explore how an under-appreciated phenotypic variable, chromosome copy number (#Chr), influences the DNA repair systems persisters use to survive fluoroquinolone treatments. We found that #Chr significantly biases the DNA repair systems used by persisters, which suggests that #Chr heterogeneity should be considered when devising strategies to eradicate these troublesome bacterial variants.
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Affiliation(s)
- Juechun Tang
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, USA
| | - Allison M. Herzfeld
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
- Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Gabrielle Leon
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, USA
| | - Mark P. Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, USA
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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8
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Yan H, Gu Z, Zhang Q, Wang Y, Cui X, Liu Y, Yu Z, Ruan R. Detoxification of copper and zinc from anaerobic digestate effluent by indigenous bacteria: Mechanisms, pathways and metagenomic analysis. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:133993. [PMID: 38461661 DOI: 10.1016/j.jhazmat.2024.133993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/05/2024] [Accepted: 03/07/2024] [Indexed: 03/12/2024]
Abstract
The presence of organic-complexed copper and zinc in anaerobic digestate effluent (ADE) poses persistent ecological toxicity. This study investigated the detoxification performance and biotic responses of indigenous bacteria against ethylene diamine tetraacetic acid (EDTA)-complexed Cu(II) and Zn(II). Heavy metals (HMs) stress induced reactive oxygen species (ROS) generation and enhanced extracellular polymeric substances (EPS) secretion. At a Cu(II) influent concentration of 20.0 mg·L-1, indigenous bacteria removed 88.2% of Cu(II) within nine days. The majority of copper and zinc sequestered by bacteria were stored in the cell envelope, with over 50% of copper and 60% of zinc being immobilized. Transmission electron microscopy mapping (TEM-mapping) revealed significant mineralization of copper and zinc on the cell wall. Proteins abundant in EPS, alongside humic acid-like substances, effectively adsorbed HMs. Indigenous bacteria exhibited the capacity to reduce cupric to the cuprous state and cupric is preferentially reduced to cuprous before reaching reducing capacity saturation. Sulfur precipitation emerges as a crucial pathway for Zn(II) removal. Metagenomic analysis indicated that indigenous bacteria upregulated genes related to HMs homeostasis, efflux, and DNA repair, enhancing its resistance to high concentrations HMs. This study provided theoretical guidance for employing bacterial consortia to eliminate HMs in complex aquatic environments.
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Affiliation(s)
- Hongbin Yan
- State Key Laboratory of Food Science and Resources, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang University, Nanchang, Jiangxi 330047, PR China
| | - Zhiqiang Gu
- State Key Laboratory of Food Science and Resources, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang University, Nanchang, Jiangxi 330047, PR China
| | - Qi Zhang
- State Key Laboratory of Food Science and Resources, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang University, Nanchang, Jiangxi 330047, PR China.
| | - Yunpu Wang
- State Key Laboratory of Food Science and Resources, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang University, Nanchang, Jiangxi 330047, PR China
| | - Xian Cui
- State Key Laboratory of Food Science and Resources, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang University, Nanchang, Jiangxi 330047, PR China
| | - Yuhuan Liu
- State Key Laboratory of Food Science and Resources, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang University, Nanchang, Jiangxi 330047, PR China
| | - Zhigang Yu
- Advanced Water Management Centre, The University of Queensland, Brisbane 4072, Australia
| | - Roger Ruan
- Center for Biorefining and Dept. of Bioproducts and Biosystems Engineering, University of Minnesota, Paul 55108, USA
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9
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Meschichi A, Rosa S. Plant chromatin on the move: an overview of chromatin mobility during transcription and DNA repair. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 118:953-962. [PMID: 36811211 DOI: 10.1111/tpj.16159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/16/2023] [Accepted: 02/19/2023] [Indexed: 06/18/2023]
Abstract
It has become increasingly clear in recent years that chromosomes are highly dynamic entities. Chromatin mobility and re-arrangement are involved in many biological processes, including gene regulation and the maintenance of genome stability. Despite extensive studies on chromatin mobility in yeast and animal systems, up until recently, not much had been investigated at this level in plants. For plants to achieve proper growth and development, they need to respond rapidly and appropriately to environmental stimuli. Therefore, understanding how chromatin mobility can support plant responses may offer profound insights into the functioning of plant genomes. In this review, we discuss the state of the art related to chromatin mobility in plants, including the available technologies for their role in various cellular processes.
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Affiliation(s)
- Anis Meschichi
- Plant Biology Department, Swedish University of Agricultural Sciences (SLU), Almas Allé 5, Uppsala, Sweden
| | - Stefanie Rosa
- Plant Biology Department, Swedish University of Agricultural Sciences (SLU), Almas Allé 5, Uppsala, Sweden
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10
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Mohr G, Yao J, Park SK, Markham L, Lambowitz AM. Mechanisms used for cDNA synthesis and site-specific integration of RNA into DNA genomes by a reverse transcriptase-Cas1 fusion protein. SCIENCE ADVANCES 2024; 10:eadk8791. [PMID: 38608016 PMCID: PMC11014452 DOI: 10.1126/sciadv.adk8791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 03/08/2024] [Indexed: 04/14/2024]
Abstract
Reverse transcriptase-Cas1 (RT-Cas1) fusion proteins found in some CRISPR systems enable spacer acquisition from both RNA and DNA, but the mechanism of RNA spacer acquisition has remained unclear. Here, we found that Marinomonas mediterranea RT-Cas1/Cas2 adds short 3'-DNA (dN) tails to RNA protospacers, enabling their direct integration into CRISPR arrays as 3'-dN-RNAs or 3'-dN-RNA/cDNA duplexes at rates comparable to similarly configured DNAs. Reverse transcription of RNA protospacers is initiated at 3' proximal sites by multiple mechanisms, including recently described de novo initiation, protein priming with any dNTP, and use of short exogenous or synthesized DNA oligomer primers, enabling synthesis of near full-length cDNAs of diverse RNAs without fixed sequence requirements. The integration of 3'-dN-RNAs or single-stranded DNAs (ssDNAs) is favored over duplexes at higher protospacer concentrations, potentially relevant to spacer acquisition from abundant pathogen RNAs or ssDNA fragments generated by phage defense nucleases. Our findings reveal mechanisms for site-specifically integrating RNA into DNA genomes with potential biotechnological applications.
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Affiliation(s)
- Georg Mohr
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX 78712, USA
| | - Jun Yao
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX 78712, USA
| | | | - Laura Markham
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX 78712, USA
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11
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Mayo-Muñoz D, Pinilla-Redondo R, Camara-Wilpert S, Birkholz N, Fineran PC. Inhibitors of bacterial immune systems: discovery, mechanisms and applications. Nat Rev Genet 2024; 25:237-254. [PMID: 38291236 DOI: 10.1038/s41576-023-00676-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2023] [Indexed: 02/01/2024]
Abstract
To contend with the diversity and ubiquity of bacteriophages and other mobile genetic elements, bacteria have developed an arsenal of immune defence mechanisms. Bacterial defences include CRISPR-Cas, restriction-modification and a growing list of mechanistically diverse systems, which constitute the bacterial 'immune system'. As a response, bacteriophages and mobile genetic elements have evolved direct and indirect mechanisms to circumvent or block bacterial defence pathways and ensure successful infection. Recent advances in methodological and computational approaches, as well as the increasing availability of genome sequences, have boosted the discovery of direct inhibitors of bacterial defence systems. In this Review, we discuss methods for the discovery of direct inhibitors, their diverse mechanisms of action and perspectives on their emerging applications in biotechnology and beyond.
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Affiliation(s)
- David Mayo-Muñoz
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Dunedin, New Zealand
| | - Rafael Pinilla-Redondo
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
- Section of Microbiology, University of Copenhagen, Copenhagen, Denmark.
| | | | - Nils Birkholz
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, Dunedin, New Zealand
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
- Genetics Otago, University of Otago, Dunedin, New Zealand.
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Dunedin, New Zealand.
- Bioprotection Aotearoa, University of Otago, Dunedin, New Zealand.
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12
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Chaudhuri R, Prasanth T, Biswas D, Mandal S, Dash J. Combating multidrug-resistance in S. pneumoniae: a G-quadruplex binding inhibitor of efflux pump and its bio-orthogonal assembly. NAR MOLECULAR MEDICINE 2024; 1:ugae005. [PMID: 38694210 PMCID: PMC11059089 DOI: 10.1093/narmme/ugae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/26/2024] [Accepted: 04/10/2024] [Indexed: 05/04/2024]
Abstract
Antibiotic resistance poses a significant global health threat, necessitating innovative strategies to combat multidrug-resistant bacterial infections. Streptococcus pneumoniae, a pathogen responsible for various infections, harbors highly conserved DNA quadruplexes in genes linked to its pathogenesis. In this study, we introduce a novel approach to counter antibiotic resistance by stabilizing G-quadruplex structures within the open reading frames of key resistance-associated genes (pmrA, recD and hsdS). We synthesized An4, a bis-anthracene derivative, using Cu(I)-catalyzed azide-alkyne cycloaddition, which exhibited remarkable binding and stabilization of the G-quadruplex in the pmrA gene responsible for drug efflux. An4 effectively permeated multidrug-resistant S. pneumoniae strains, leading to a substantial 12.5-fold reduction in ciprofloxacin resistance. Furthermore, An4 downregulated pmrA gene expression, enhancing drug retention within bacterial cells. Remarkably, the pmrA G-quadruplex cloned into the pET28a(+) plasmid transformed into Escherichia coli BL21 cells can template Cu-free bio-orthogonal synthesis of An4 from its corresponding alkyne and azide fragments. This study presents a pioneering strategy to combat antibiotic resistance by genetically reducing drug efflux pump expression through G-quadruplex stabilization, offering promising avenues for addressing antibiotic resistance.
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Affiliation(s)
- Ritapa Chaudhuri
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, West-Bengal 700032, India
| | - Thumpati Prasanth
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, West-Bengal 700032, India
| | - Debasmita Biswas
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, West-Bengal 700032, India
| | - Subhranshu Mandal
- Laboratory Medicine, Chittaranjan National Cancer Institute, Kolkata, West Bengal 700156, India
| | - Jyotirmayee Dash
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, West-Bengal 700032, India
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13
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Pavankumar TL, Wong C, Wong YK, Spies M, Kowalczykowski S. Trans-complementation by the RecB nuclease domain of RecBCD enzyme reveals new insight into RecA loading upon χ recognition. Nucleic Acids Res 2024; 52:2578-2589. [PMID: 38261972 PMCID: PMC10954480 DOI: 10.1093/nar/gkae007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/28/2023] [Accepted: 01/03/2024] [Indexed: 01/25/2024] Open
Abstract
The loading of RecA onto ssDNA by RecBCD is an essential step of RecBCD-mediated homologous recombination. RecBCD facilitates RecA-loading onto ssDNA in a χ-dependent manner via its RecB nuclease domain (RecBn). Before recognition of χ, RecBn is sequestered through interactions with RecBCD. It was proposed that upon χ-recognition, RecBn undocks, allowing RecBn to swing out via a contiguous 70 amino acid linker to reveal the RecA-loading surface, and then recruit and load RecA onto ssDNA. We tested this hypothesis by examining the interactions between RecBn (RecB928-1180) and truncated RecBCD (RecB1-927CD) lacking the nuclease domain. The reconstituted complex of RecB1-927CD and RecBn is functional in vitro and in vivo. Our results indicate that despite being covalently severed from RecB1-927CD, RecBn can still load RecA onto ssDNA, establishing that RecBn does not function while only remaining tethered to the RecBCD complex via the linker. Instead, RecBCD undergoes a χ-induced intramolecular rearrangement to reveal the RecA-loading surface.
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Affiliation(s)
- Theetha L Pavankumar
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - C Jason Wong
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Yun Ka Wong
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Maria Spies
- Department of Biochemistry, University of Iowa, Carver College of Medicine, Iowa City, IA 52242, USA
| | - Stephen C Kowalczykowski
- Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
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14
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Dicks LMT, Vermeulen W. Bacteriophage-Host Interactions and the Therapeutic Potential of Bacteriophages. Viruses 2024; 16:478. [PMID: 38543843 PMCID: PMC10975011 DOI: 10.3390/v16030478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 05/23/2024] Open
Abstract
Healthcare faces a major problem with the increased emergence of antimicrobial resistance due to over-prescribing antibiotics. Bacteriophages may provide a solution to the treatment of bacterial infections given their specificity. Enzymes such as endolysins, exolysins, endopeptidases, endosialidases, and depolymerases produced by phages interact with bacterial surfaces, cell wall components, and exopolysaccharides, and may even destroy biofilms. Enzymatic cleavage of the host cell envelope components exposes specific receptors required for phage adhesion. Gram-positive bacteria are susceptible to phage infiltration through their peptidoglycan, cell wall teichoic acid (WTA), lipoteichoic acids (LTAs), and flagella. In Gram-negative bacteria, lipopolysaccharides (LPSs), pili, and capsules serve as targets. Defense mechanisms used by bacteria differ and include physical barriers (e.g., capsules) or endogenous mechanisms such as clustered regularly interspaced palindromic repeat (CRISPR)-associated protein (Cas) systems. Phage proteins stimulate immune responses against specific pathogens and improve antibiotic susceptibility. This review discusses the attachment of phages to bacterial cells, the penetration of bacterial cells, the use of phages in the treatment of bacterial infections, and the limitations of phage therapy. The therapeutic potential of phage-derived proteins and the impact that genomically engineered phages may have in the treatment of infections are summarized.
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Affiliation(s)
- Leon M. T. Dicks
- Department of Microbiology, Stellenbosch University, Stellenbosch 7600, South Africa;
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15
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Amundsen SK, Smith GR. Chi hotspot Control of RecBCD Helicase-nuclease: Enzymatic Tests Support the Intramolecular Signal-transduction Model. J Mol Biol 2024; 436:168482. [PMID: 38331210 PMCID: PMC10947171 DOI: 10.1016/j.jmb.2024.168482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/11/2024] [Accepted: 02/02/2024] [Indexed: 02/10/2024]
Abstract
Repair of broken DNA is essential for life; the reactions involved can also promote genetic recombination to aid evolution. In Escherichia coli, RecBCD enzyme is required for the major pathway of these events. RecBCD is a complex ATP-dependent DNA helicase with nuclease activity controlled by Chi recombination hotspots (5'-GCTGGTGG-3'). During rapid DNA unwinding, when Chi is in a RecC tunnel, RecB nuclease nicks DNA at Chi. Here, we test our signal transduction model - upon binding Chi (step 1), RecC signals RecD helicase to stop unwinding (step 2); RecD then signals RecB (step 3) to nick at Chi (step 4) and to begin loading RecA DNA strand-exchange protein (step 5). We discovered that ATP-γ-S, like the small molecule RecBCD inhibitor NSAC1003, causes RecBCD to nick DNA, independent of Chi, at novel positions determined by the DNA substrate length. Two RecB ATPase-site mutants nick at novel positions determined by their RecB:RecD helicase rate ratios. In each case, we find that nicking at the novel position requires steps 3 and 4 but not step 1 or 2, as shown by mutants altered at the intersubunit contacts specific for each step; nicking also requires RecD helicase and RecB nuclease activities. Thus, altering the RecB ATPase site, by small molecules or mutation, sensitizes RecD to signal RecB to nick DNA (steps 4 and 3, respecitvely) without the signal from RecC or Chi (steps 1 and 2). These new, enzymatic results strongly support the signal transduction model and provide a paradigm for studying other complex enzymes.
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Affiliation(s)
- Susan K Amundsen
- Division of Basic Sciences, Fred Hutchinson Cancer Center, 1100 Farview Avenue North, A1-162, Seattle, WA 98109, USA
| | - Gerald R Smith
- Division of Basic Sciences, Fred Hutchinson Cancer Center, 1100 Farview Avenue North, A1-162, Seattle, WA 98109, USA.
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16
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Roisné-Hamelin F, Liu HW, Taschner M, Li Y, Gruber S. Structural basis for plasmid restriction by SMC JET nuclease. Mol Cell 2024; 84:883-896.e7. [PMID: 38309275 DOI: 10.1016/j.molcel.2024.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/06/2023] [Accepted: 01/09/2024] [Indexed: 02/05/2024]
Abstract
DNA loop-extruding SMC complexes play crucial roles in chromosome folding and DNA immunity. Prokaryotic SMC Wadjet (JET) complexes limit the spread of plasmids through DNA cleavage, yet the mechanisms for plasmid recognition are unresolved. We show that artificial DNA circularization renders linear DNA susceptible to JET nuclease cleavage. Unlike free DNA, JET cleaves immobilized plasmid DNA at a specific site, the plasmid-anchoring point, showing that the anchor hinders DNA extrusion but not DNA cleavage. Structures of plasmid-bound JetABC reveal two presumably stalled SMC motor units that are drastically rearranged from the resting state, together entrapping a U-shaped DNA segment, which is further converted to kinked V-shaped cleavage substrate by JetD nuclease binding. Our findings uncover mechanical bending of residual unextruded DNA as molecular signature for plasmid recognition and non-self DNA elimination. We moreover elucidate key elements of SMC loop extrusion, including the motor direction and the structure of a DNA-holding state.
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Affiliation(s)
- Florian Roisné-Hamelin
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Hon Wing Liu
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Michael Taschner
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Yan Li
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Stephan Gruber
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland.
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17
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Liu S, Liu H, Wang X, Shi L. The immune system of prokaryotes: potential applications and implications for gene editing. Biotechnol J 2024; 19:e2300352. [PMID: 38403433 DOI: 10.1002/biot.202300352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 11/30/2023] [Accepted: 12/28/2023] [Indexed: 02/27/2024]
Abstract
Gene therapy has revolutionized the treatment of genetic diseases. Spearheading this revolution are sophisticated genome editing methods such as TALENs, ZFNs, and CRISPR-Cas, which trace their origins back to prokaryotic immune systems. Prokaryotes have developed various antiviral defense systems to combat viral attacks and the invasion of genetic elements. The comprehension of these defense mechanisms has paved the way for the development of indispensable tools in molecular biology. Among them, restriction endonuclease originates from the innate immune system of bacteria. The CRISPR-Cas system, a widely applied genome editing technology, is derived from the prokaryotic adaptive immune system. Single-base editing is a precise editing tool based on CRISPR-Cas system that involves deamination of target base. It is worth noting that prokaryotes possess deamination enzymes as part of their defense arsenal over foreign genetic material. Furthermore, prokaryotic Argonauts (pAgo) proteins, also function in anti-phage defense, play an important role in complementing the CRISPR-Cas system by addressing certain limitations it may have. Recent studies have also shed light on the significance of Retron, a reverse transcription transposon previously showed potential in genome editing, has also come to light in the realm of prokaryotic immunity. These noteworthy findings highlight the importance of studying prokaryotic immune system for advancing genome editing techniques. Here, both the origin of prokaryotic immunity underlying aforementioned genome editing tools, and potential applications of deaminase, pAgo protein and reverse transcriptase in genome editing among prokaryotes were introduced, thus emphasizing the fundamental mechanism and significance of prokaryotic immunity.
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Affiliation(s)
- Siyang Liu
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Hongling Liu
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Xue Wang
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Lei Shi
- School of Life Sciences, Chongqing University, Chongqing, China
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18
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Bonde NJ, Kozlov AG, Cox MM, Lohman TM, Keck JL. Molecular insights into the prototypical single-stranded DNA-binding protein from E. coli. Crit Rev Biochem Mol Biol 2024; 59:99-127. [PMID: 38770626 PMCID: PMC11209772 DOI: 10.1080/10409238.2024.2330372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 03/11/2024] [Indexed: 05/22/2024]
Abstract
The SSB protein of Escherichia coli functions to bind single-stranded DNA wherever it occurs during DNA metabolism. Depending upon conditions, SSB occurs in several different binding modes. In the course of its function, SSB diffuses on ssDNA and transfers rapidly between different segments of ssDNA. SSB interacts with many other proteins involved in DNA metabolism, with 22 such SSB-interacting proteins, or SIPs, defined to date. These interactions chiefly involve the disordered and conserved C-terminal residues of SSB. When not bound to ssDNA, SSB can aggregate to form a phase-separated biomolecular condensate. Current understanding of the properties of SSB and the functional significance of its many intermolecular interactions are summarized in this review.
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Affiliation(s)
- Nina J. Bonde
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alexander G. Kozlov
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - Michael M. Cox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Timothy M. Lohman
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - James L. Keck
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
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19
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Fazio NT, Mersch KN, Hao L, Lohman TM. E. coli RecB Nuclease Domain Regulates RecBCD Helicase Activity but not Single Stranded DNA Translocase Activity. J Mol Biol 2024; 436:168381. [PMID: 38081382 PMCID: PMC11131135 DOI: 10.1016/j.jmb.2023.168381] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 12/23/2023]
Abstract
Much is still unknown about the mechanisms by which helicases unwind duplex DNA. Whereas structure-based models describe DNA unwinding as occurring by the ATPase motors mechanically pulling the DNA duplex across a wedge domain in the helicase, biochemical data show that processive DNA unwinding by E. coli RecBCD helicase can occur in the absence of ssDNA translocation by the canonical RecB and RecD motors. Here we show that DNA unwinding is not a simple consequence of ssDNA translocation by the motors. Using stopped-flow fluorescence approaches, we show that a RecB nuclease domain deletion variant (RecBΔNucCD) unwinds dsDNA at significantly slower rates than RecBCD, while the ssDNA translocation rate is unaffected. This effect is primarily due to the absence of the nuclease domain since a nuclease-dead mutant (RecBD1080ACD), which retains the nuclease domain, showed no change in ssDNA translocation or dsDNA unwinding rates relative to RecBCD on short DNA substrates (≤60 base pairs). Hence, ssDNA translocation is not rate-limiting for DNA unwinding. RecBΔNucCD also initiates unwinding much slower than RecBCD from a blunt-ended DNA. RecBΔNucCD also unwinds DNA ∼two-fold slower than RecBCD on long DNA (∼20 kilo base pair) in single molecule optical tweezer experiments, although the rates for RecBD1080ACD unwinding are intermediate between RecBCD and RecBΔNucCD. Surprisingly, significant pauses in DNA unwinding occur even in the absence of chi (crossover hotspot instigator) sites. We hypothesize that the nuclease domain influences the rate of DNA base pair melting, possibly allosterically and that RecBΔNucCD may mimic a post-chi state of RecBCD.
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Affiliation(s)
- Nicole T Fazio
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States
| | - Kacey N Mersch
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States
| | - Linxuan Hao
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States
| | - Timothy M Lohman
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, United States.
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20
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Amundsen SK, Smith GR. RecBCD enzyme: mechanistic insights from mutants of a complex helicase-nuclease. Microbiol Mol Biol Rev 2023; 87:e0004123. [PMID: 38047637 PMCID: PMC10732027 DOI: 10.1128/mmbr.00041-23] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023] Open
Abstract
SUMMARYRecBCD enzyme is a multi-functional protein that initiates the major pathway of homologous genetic recombination and DNA double-strand break repair in Escherichia coli. It is also required for high cell viability and aids proper DNA replication. This 330-kDa, three-subunit enzyme is one of the fastest, most processive helicases known and contains a potent nuclease controlled by Chi sites, hotspots of recombination, in DNA. RecBCD undergoes major changes in activity and conformation when, during DNA unwinding, it encounters Chi (5'-GCTGGTGG-3') and nicks DNA nearby. Here, we discuss the multitude of mutations in each subunit that affect one or another activity of RecBCD and its control by Chi. These mutants have given deep insights into how the multiple activities of this complex enzyme are coordinated and how it acts in living cells. Similar studies could help reveal how other complex enzymes are controlled by inter-subunit interactions and conformational changes.
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Affiliation(s)
| | - Gerald R. Smith
- Fred Hutchinson Cancer Center Seattle, Seattle, Washington, USA
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21
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Hurley KE, Banerjee SK, Stephens AC, Scribner MR, Cooper VS, Richardson AR. The contribution of DNA repair pathways to Staphylococcus aureus fitness and fidelity during nitric oxide stress. mBio 2023; 14:e0215623. [PMID: 37948342 PMCID: PMC10746251 DOI: 10.1128/mbio.02156-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/04/2023] [Indexed: 11/12/2023] Open
Abstract
IMPORTANCE Pathogenic bacteria must evolve various mechanisms in order to evade the host immune response that they are infecting. One aspect of the primary host immune response to an infection is the production of an inflammatory effector component, nitric oxide (NO⋅). Staphylococcus aureus has uniquely evolved a diverse array of strategies to circumvent the inhibitory activity of nitric oxide. One such mechanism by which S. aureus has evolved allows the pathogen to survive and maintain its genomic integrity in this environment. For instance, here, our results suggest that S. aureus employs several DNA repair pathways to ensure replicative fitness and fidelity under NO⋅ stress. Thus, our study presents evidence of an additional strategy that allows S. aureus to evade the cytotoxic effects of host NO⋅.
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Affiliation(s)
- Kelly E. Hurley
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Srijon K. Banerjee
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Amelia C. Stephens
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michelle R. Scribner
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Vaughn S. Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anthony R. Richardson
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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22
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Noda S, Akanuma G, Keyamura K, Hishida T. RecN spatially and temporally controls RecA-mediated repair of DNA double-strand breaks. J Biol Chem 2023; 299:105466. [PMID: 37979912 PMCID: PMC10714372 DOI: 10.1016/j.jbc.2023.105466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/20/2023] Open
Abstract
RecN, a bacterial structural maintenance of chromosomes-like protein, plays an important role in maintaining genomic integrity by facilitating the repair of DNA double-strand breaks (DSBs). However, how RecN-dependent chromosome dynamics are integrated with DSB repair remains unclear. Here, we investigated the dynamics of RecN in response to DNA damage by inducing RecN from the PBAD promoter at different time points. We found that mitomycin C (MMC)-treated ΔrecN cells exhibited nucleoid fragmentation and reduced cell survival; however, when RecN was induced with arabinose in MMC-exposed ΔrecN cells, it increased a level of cell viability to similar extent as WT cells. Furthermore, in MMC-treated ΔrecN cells, arabinose-induced RecN colocalized with RecA in nucleoid gaps between fragmented nucleoids and restored normal nucleoid structures. These results suggest that the aberrant nucleoid structures observed in MMC-treated ΔrecN cells do not represent catastrophic chromosome disruption but rather an interruption of the RecA-mediated process. Thus, RecN can resume DSB repair by stimulating RecA-mediated homologous recombination, even when chromosome integrity is compromised. Our data demonstrate that RecA-mediated presynapsis and synapsis are spatiotemporally separable, wherein RecN is involved in facilitating both processes presumably by orchestrating the dynamics of both RecA and chromosomes, highlighting the essential role of RecN in the repair of DSBs.
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Affiliation(s)
- Shunsuke Noda
- Department of Molecular Biology, Graduate School of Science, Gakushuin University, Tokyo, Japan
| | - Genki Akanuma
- Department of Molecular Biology, Graduate School of Science, Gakushuin University, Tokyo, Japan
| | - Kenji Keyamura
- Department of Molecular Biology, Graduate School of Science, Gakushuin University, Tokyo, Japan
| | - Takashi Hishida
- Department of Molecular Biology, Graduate School of Science, Gakushuin University, Tokyo, Japan.
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23
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Fazio N, Mersch KN, Hao L, Lohman TM. E. coli RecBCD Nuclease Domain Regulates Helicase Activity but not Single Stranded DNA Translocase Activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.13.561901. [PMID: 37905078 PMCID: PMC10614803 DOI: 10.1101/2023.10.13.561901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Much is still unknown about the mechanisms by which helicases unwind duplex DNA. Whereas structure-based models describe DNA unwinding as a consequence of mechanically pulling the DNA duplex across a wedge domain in the helicase by the single stranded (ss)DNA translocase activity of the ATPase motors, biochemical data indicate that processive DNA unwinding by the E. coli RecBCD helicase can occur in the absence of ssDNA translocation of the canonical RecB and RecD motors. Here, we present evidence that dsDNA unwinding is not a simple consequence of ssDNA translocation by the RecBCD motors. Using stopped-flow fluorescence approaches, we show that a RecB nuclease domain deletion variant (RecB ΔNuc CD) unwinds dsDNA at significantly slower rates than RecBCD, while the rate of ssDNA translocation is unaffected. This effect is primarily due to the absence of the nuclease domain and not the absence of the nuclease activity, since a nuclease-dead mutant (RecB D1080A CD), which retains the nuclease domain, showed no significant change in rates of ssDNA translocation or dsDNA unwinding relative to RecBCD on short DNA substrates (≤ 60 base pairs). This indicates that ssDNA translocation is not rate-limiting for DNA unwinding. RecB ΔNuc CD also initiates unwinding much slower than RecBCD from a blunt-ended DNA, although it binds with higher affinity than RecBCD. RecB ΔNuc CD also unwinds DNA ∼two-fold slower than RecBCD on long DNA (∼20 kilo base pair) in single molecule optical tweezer experiments, although the rates for RecB D1080A CD unwinding are intermediate between RecBCD and RecB ΔNuc CD. Surprisingly, significant pauses occur even in the absence of chi (crossover hotspot instigator) sites. We hypothesize that the nuclease domain influences the rate of DNA base pair melting, rather than DNA translocation, possibly allosterically. Since the rate of DNA unwinding by RecBCD also slows after it recognizes a chi sequence, RecB ΔNuc CD may mimic a post- chi state of RecBCD.
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24
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Georjon H, Bernheim A. The highly diverse antiphage defence systems of bacteria. Nat Rev Microbiol 2023; 21:686-700. [PMID: 37460672 DOI: 10.1038/s41579-023-00934-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 86.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2023] [Indexed: 09/14/2023]
Abstract
Bacteria and their viruses have coevolved for billions of years. This ancient and still ongoing arms race has led bacteria to develop a vast antiphage arsenal. The development of high-throughput screening methods expanded our knowledge of defence systems from a handful to more than a hundred systems, unveiling many different molecular mechanisms. These findings reveal that bacterial immunity is much more complex than previously thought. In this Review, we explore recently discovered bacterial antiphage defence systems, with a particular focus on their molecular diversity, and discuss the ecological and evolutionary drivers and implications of the existing diversity of antiphage defence mechanisms.
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Affiliation(s)
- Héloïse Georjon
- Molecular Diversity of Microbes Lab, Institut Pasteur, Université Paris Cité, INSERM, Paris, France
| | - Aude Bernheim
- Molecular Diversity of Microbes Lab, Institut Pasteur, Université Paris Cité, INSERM, Paris, France.
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25
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Akritidou K, Thurtle-Schmidt BH. OLD family nuclease function across diverse anti-phage defense systems. Front Microbiol 2023; 14:1268820. [PMID: 37840731 PMCID: PMC10568477 DOI: 10.3389/fmicb.2023.1268820] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/14/2023] [Indexed: 10/17/2023] Open
Abstract
Bacteriophages constitute a ubiquitous threat to bacteria, and bacteria have evolved numerous anti-phage defense systems to protect themselves. These systems include well-studied phenomena such as restriction endonucleases and CRISPR, while emerging studies have identified many new anti-phage defense systems whose mechanisms are unknown or poorly understood. Some of these systems involve overcoming lysogenization defect (OLD) nucleases, a family of proteins comprising an ABC ATPase domain linked to a Toprim nuclease domain. Despite being discovered over 50 years ago, OLD nuclease function remained mysterious until recent biochemical, structural, and bioinformatic studies revealed that OLD nucleases protect bacteria by functioning in diverse anti-phage defense systems including the Gabija system and retrons. In this review we will highlight recent discoveries in OLD protein function and their involvement in multiple discrete anti-phage defense systems.
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26
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Mohr G, Yao J, Park SK, Markham LM, Lambowitz AM. Mechanisms used for cDNA synthesis and site-specific integration of RNA into DNA genomes by a reverse transcriptase-Cas1 fusion protein. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555893. [PMID: 37693417 PMCID: PMC10491204 DOI: 10.1101/2023.09.01.555893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Reverse transcriptase-Cas1 (RT-Cas1) fusion proteins found in some CRISPR systems enable spacer acquisition from both RNA and DNA, but the mechanism of RNA spacer acquisition has remained unclear. Here, we found Marinomonas mediterranea RT-Cas1/Cas2 adds short 3'-DNA (dN) tails to RNA protospacers enabling their direct integration into CRISPR arrays as 3'-dN-RNA/cDNA duplexes or 3'-dN-RNAs at rates comparable to similarly configured DNAs. Reverse transcription of RNA protospacers occurs by multiple mechanisms, including recently described de novo initiation, protein priming with any dNTP, and use of short exogenous or synthesized DNA oligomer primers, enabling synthesis of cDNAs from diverse RNAs without fixed sequence requirements. The integration of 3'-dN-RNAs or single-stranded (ss) DNAs is favored over duplexes at higher protospacer concentrations, potentially relevant to spacer acquisition from abundant pathogen RNAs or ssDNA fragments generated by phage-defense nucleases. Our findings reveal novel mechanisms for site-specifically integrating RNA into DNA genomes with potential biotechnological applications.
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Affiliation(s)
- Georg Mohr
- Departments of Molecular Biosciences and Oncology University of Texas at Austin Austin TX, 78712
| | - Jun Yao
- Departments of Molecular Biosciences and Oncology University of Texas at Austin Austin TX, 78712
| | | | - Laura M. Markham
- Departments of Molecular Biosciences and Oncology University of Texas at Austin Austin TX, 78712
| | - Alan M. Lambowitz
- Departments of Molecular Biosciences and Oncology University of Texas at Austin Austin TX, 78712
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27
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Brooks R, Morici L, Sandoval N. Cell Free Bacteriophage Synthesis from Engineered Strains Improves Yield. ACS Synth Biol 2023; 12:2418-2431. [PMID: 37548960 PMCID: PMC10443043 DOI: 10.1021/acssynbio.3c00239] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Indexed: 08/08/2023]
Abstract
Phage therapy to treat life-threatening drug-resistant infections has been hampered by technical challenges in phage production. Cell-free bacteriophage synthesis (CFBS) can overcome the limitations of standard phage production methods by manufacturing phage virions in vitro. CFBS mimics intracellular phage assembly using transcription/translation machinery (TXTL) harvested from bacterial lysates and combined with reagents to synthesize proteins encoded by a phage genomic DNA template. These systems may enable rapid phage production and engineering to accelerate phages from bench-to-bedside. TXTL harvested from wild type or commonly used bacterial strains was not optimized for bacteriophage production. Here, we demonstrate that TXTL from genetically modified E. coli BL21 can be used to enhance phage T7 yields in vitro by CFBS. Expression of 18 E. coli BL21 genes was manipulated by inducible CRISPR interference (CRISPRi) mediated by nuclease deficient Cas12a from F. novicida (dFnCas12a) to identify genes implicated in T7 propagation as positive or negative effectors. Genes shown to have a significant effect were overexpressed (positive effectors) or repressed (negative effectors) to modify the genetic background of TXTL harvested for CFBS. Phage T7 CFBS yields were improved by up to 10-fold in vitro through overexpression of translation initiation factor IF-3 (infC) and small RNAs OxyS and CyaR and by repression of RecC subunit exonuclease RecBCD. Continued improvement of CFBS will mitigate phage manufacturing bottlenecks and lower hurdles to widespread adoption of phage therapy.
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Affiliation(s)
- Rani Brooks
- Interdisciplinary
Bioinnovation PhD Program, Tulane University, New Orleans, Louisiana 70118-5665, United
States
| | - Lisa Morici
- Department
of Microbiology and Immunology, Tulane University
School of Medicine, New Orleans, Louisiana 70112, United States
| | - Nicholas Sandoval
- Department
of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, United States
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28
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Soler-Garzón A, Goldoff D, Thornton A, Swisher Grimm KD, Hart JP, Song Q, Strausbaugh CA, Miklas PN. A robust SNP-haplotype assay for Bct gene region conferring resistance to beet curly top virus in common bean ( Phaseolus vulgaris L.). FRONTIERS IN PLANT SCIENCE 2023; 14:1215950. [PMID: 37521933 PMCID: PMC10382175 DOI: 10.3389/fpls.2023.1215950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 06/12/2023] [Indexed: 08/01/2023]
Abstract
Beet curly top virus (BCTV), which is synonymous with curly top virus (CTV), causes significant yield loss in common bean (snap and dry beans) cultivars and several other important crops. Common bean cultivars have been found to be resistant to CTV, but screening for resistance is challenging due to the cyclical nature of epidemics and spotty feeding by the leafhopper that vectors the virus. We used an SNP dataset for the Snap Bean Association Panel (SnAP) agro-inoculated with CTV-Logan (CA/Logan) strain to locate the Bct gene region to a 1.7-Mb interval on chromosome Pv07 using genome-wide association study (GWAS) analysis. Recombinant lines from the SnAP were used to further narrow the Bct region to a 58.0-kb interval. A missense SNP (S07_2970381) in candidate gene Phvul.007G036300 Exonuclease V (EXO5) was identified as the most likely causal mutation, and it was the most significant SNP detected by GWAS in a dry bean population (DBP) naturally infected by the CTV-Worland (Wor) strain. Tm-shift assay markers developed for SNP S07_2970381 and two linked SNPs, S07_2970276 and S07_2966197, were useful for tracking different origins of the Bct EXO5 candidate gene resistance to CTV in common bean. The three SNPs identified four haplotypes, with haplotype 3-1 (Haplo3-1) of Middle American origin associated with the highest levels of CTV resistance. This SNP-haplotype assay will enable breeders to track resistance sources and to develop cultivars with better CTV resistance.
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Affiliation(s)
- Alvaro Soler-Garzón
- Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, WA, United States
| | - Deidrah Goldoff
- Global Pathology Support Platform, HM Clause Seed Company, Davis, CA, United States
| | - Alyson Thornton
- Global Pathology Support Platform, HM Clause Seed Company, Davis, CA, United States
| | - Kylie D. Swisher Grimm
- Temperate Tree Fruit and Vegetable Research Unit, United States Department of Agriculture Agricultural Research Service (USDA-ARS), Prosser, WA, United States
| | - John P. Hart
- Tropical Agriculture Research Station, United States Department of Agriculture Agricultural Research Service (USDA-ARS), Mayagüez, Puerto Rico
| | - Qijian Song
- Soybean Genomics and Improvement Laboratory, United States Department of Agriculture Agricultural Research Service (USDA-ARS), Beltsville, MD, United States
| | - Carl A. Strausbaugh
- Northwest Irrigation and Soils Research Laboratory, United States Department of Agriculture Agricultural Research Service (USDA-ARS), Kimberly, ID, United States
| | - Phillip N. Miklas
- Grain Legume Genetics and Physiology Research Unit, United States Department of Agriculture Agricultural Research Service (USDA-ARS), Prosser, WA, United States
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29
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Prentiss M, Wang D, Fu J, Prévost C, Godoy-Carter V, Kleckner N, Danilowicz C. Highly mismatch-tolerant homology testing by RecA could explain how homology length affects recombination. PLoS One 2023; 18:e0288611. [PMID: 37440583 PMCID: PMC10343044 DOI: 10.1371/journal.pone.0288611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 07/02/2023] [Indexed: 07/15/2023] Open
Abstract
In E. coli, double strand breaks (DSBs) are resected and loaded with RecA protein. The genome is then rapidly searched for a sequence that is homologous to the DNA flanking the DSB. Mismatches in homologous partners are rare, suggesting that RecA should rapidly reject mismatched recombination products; however, this is not the case. Decades of work have shown that long lasting recombination products can include many mismatches. In this work, we show that in vitro RecA forms readily observable recombination products when 16% of the bases in the product are mismatched. We also consider various theoretical models of mismatch-tolerant homology testing. The models test homology by comparing the sequences of Ltest bases in two single-stranded DNAs (ssDNA) from the same genome. If the two sequences pass the homology test, the pairing between the two ssDNA becomes permanent. Stringency is the fraction of permanent pairings that join ssDNA from the same positions in the genome. We applied the models to both randomly generated genomes and bacterial genomes. For both randomly generated genomes and bacterial genomes, the models show that if no mismatches are accepted stringency is ∼ 99% when Ltest = 14 bp. For randomly generated genomes, stringency decreases with increasing mismatch tolerance, and stringency improves with increasing Ltest. In contrast, in bacterial genomes when Ltest ∼ 75 bp, stringency is ∼ 99% for both mismatch-intolerant and mismatch-tolerant homology testing. Furthermore, increasing Ltest does not improve stringency because most incorrect pairings join different copies of repeats. In sum, for bacterial genomes highly mismatch tolerant homology testing of 75 bp provides the same stringency as homology testing that rejects all mismatches and testing more than ∼75 base pairs is not useful. Interestingly, in vivo commitment to recombination typically requires homology testing of ∼ 75 bp, consistent with highly mismatch intolerant testing.
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Affiliation(s)
- Mara Prentiss
- Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America
| | - Dianzhuo Wang
- Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America
| | - Jonathan Fu
- Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America
| | - Chantal Prévost
- Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, Paris, France
| | - Veronica Godoy-Carter
- Department of Biology, Northeastern University, Boston, Massachusetts, United States of America
| | - Nancy Kleckner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Claudia Danilowicz
- Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America
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30
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Mayo-Muñoz D, Pinilla-Redondo R, Birkholz N, Fineran PC. A host of armor: Prokaryotic immune strategies against mobile genetic elements. Cell Rep 2023; 42:112672. [PMID: 37347666 DOI: 10.1016/j.celrep.2023.112672] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/22/2023] [Accepted: 06/02/2023] [Indexed: 06/24/2023] Open
Abstract
Prokaryotic adaptation is strongly influenced by the horizontal acquisition of beneficial traits via mobile genetic elements (MGEs), such as viruses/bacteriophages and plasmids. However, MGEs can also impose a fitness cost due to their often parasitic nature and differing evolutionary trajectories. In response, prokaryotes have evolved diverse immune mechanisms against MGEs. Recently, our understanding of the abundance and diversity of prokaryotic immune systems has greatly expanded. These defense systems can degrade the invading genetic material, inhibit genome replication, or trigger abortive infection, leading to population protection. In this review, we highlight these strategies, focusing on the most recent discoveries. The study of prokaryotic defenses not only sheds light on microbial evolution but also uncovers novel enzymatic activities with promising biotechnological applications.
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Affiliation(s)
- David Mayo-Muñoz
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Genetics Otago, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Rafael Pinilla-Redondo
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Nils Birkholz
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Genetics Otago, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Bioprotection Aotearoa, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Genetics Otago, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Bioprotection Aotearoa, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
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31
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Olina A, Agapov A, Yudin D, Sutormin D, Galivondzhyan A, Kuzmenko A, Severinov K, Aravin AA, Kulbachinskiy A. Bacterial Argonaute Proteins Aid Cell Division in the Presence of Topoisomerase Inhibitors in Escherichia coli. Microbiol Spectr 2023; 11:e0414622. [PMID: 37102866 PMCID: PMC10269773 DOI: 10.1128/spectrum.04146-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/29/2023] [Indexed: 04/28/2023] Open
Abstract
Prokaryotic Argonaute (pAgo) proteins are guide-dependent nucleases that function in host defense against invaders. Recently, it was shown that TtAgo from Thermus thermophilus also participates in the completion of DNA replication by decatenating chromosomal DNA. Here, we show that two pAgos from cyanobacteria Synechococcus elongatus (SeAgo) and Limnothrix rosea (LrAgo) are active in heterologous Escherichia coli and aid cell division in the presence of the gyrase inhibitor ciprofloxacin, depending on the host double-strand break repair machinery. Both pAgos are preferentially loaded with small guide DNAs (smDNAs) derived from the sites of replication termination. Ciprofloxacin increases the amounts of smDNAs from the termination region and from the sites of genomic DNA cleavage by gyrase, suggesting that smDNA biogenesis depends on DNA replication and is stimulated by gyrase inhibition. Ciprofloxacin enhances asymmetry in the distribution of smDNAs around Chi sites, indicating that it induces double-strand breaks that serve as a source of smDNA during their processing by RecBCD. While active in E. coli, SeAgo does not protect its native host S. elongatus from ciprofloxacin. These results suggest that pAgo nucleases may help to complete replication of chromosomal DNA by promoting chromosome decatenation or participating in the processing of gyrase cleavage sites, and may switch their functional activities depending on the host species. IMPORTANCE Prokaryotic Argonautes (pAgos) are programmable nucleases with incompletely understood functions in vivo. In contrast to eukaryotic Argonautes, most studied pAgos recognize DNA targets. Recent studies suggested that pAgos can protect bacteria from invader DNA and counteract phage infection and may also have other functions including possible roles in DNA replication, repair, and gene regulation. Here, we have demonstrated that two cyanobacterial pAgos, SeAgo and LrAgo, can assist DNA replication and facilitate cell division in the presence of topoisomerase inhibitors in Escherichia coli. They are specifically loaded with small guide DNAs from the region of replication termination and protect the cells from the action of the gyrase inhibitor ciprofloxacin, suggesting that they help to complete DNA replication and/or repair gyrase-induced breaks. The results show that pAgo proteins may serve as a backup to topoisomerases under conditions unfavorable for DNA replication and may modulate the resistance of host bacterial strains to antibiotics.
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Affiliation(s)
- Anna Olina
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Aleksei Agapov
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Denis Yudin
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Dmitry Sutormin
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | | | - Anton Kuzmenko
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | | | - Alexei A. Aravin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Andrey Kulbachinskiy
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow, Russia
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
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32
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Lisitskaya L, Kropocheva E, Agapov A, Prostova M, Panteleev V, Yudin D, Ryazansky S, Kuzmenko A, Aravin A, Esyunina D, Kulbachinskiy A. Bacterial Argonaute nucleases reveal different modes of DNA targeting in vitro and in vivo. Nucleic Acids Res 2023; 51:5106-5124. [PMID: 37094066 PMCID: PMC10250240 DOI: 10.1093/nar/gkad290] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 04/26/2023] Open
Abstract
Prokaryotic Argonaute proteins (pAgos) are homologs of eukaryotic Argonautes (eAgos) and are also thought to play a role in cell defense against invaders. However, pAgos are much more diverse than eAgos and little is known about their functional activities and target specificities in vivo. Here, we describe five pAgos from mesophilic bacteria that act as programmable DNA endonucleases and analyze their ability to target chromosomal and invader DNA. In vitro, the analyzed proteins use small guide DNAs for precise cleavage of single-stranded DNA at a wide range of temperatures. Upon their expression in Escherichia coli, all five pAgos are loaded with small DNAs preferentially produced from plasmids and chromosomal regions of replication termination. One of the tested pAgos, EmaAgo from Exiguobacterium marinum, can induce DNA interference between homologous sequences resulting in targeted processing of multicopy plasmid and genomic elements. EmaAgo also protects bacteria from bacteriophage infection, by loading phage-derived guide DNAs and decreasing phage DNA content and phage titers. Thus, the ability of pAgos to target multicopy elements may be crucial for their protective function. The wide spectrum of pAgo activities suggests that they may have diverse functions in vivo and paves the way for their use in biotechnology.
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Affiliation(s)
- Lidiya Lisitskaya
- Institute of Gene Biology, Russian Academy of Sciences, Moscow119334, Russia
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
| | - Ekaterina Kropocheva
- Institute of Gene Biology, Russian Academy of Sciences, Moscow119334, Russia
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
| | - Aleksei Agapov
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
| | - Maria Prostova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow119334, Russia
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
| | - Vladimir Panteleev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow119334, Russia
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny141700, Russia
| | - Denis Yudin
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
| | - Sergei Ryazansky
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
| | - Anton Kuzmenko
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Alexei A Aravin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Daria Esyunina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow119334, Russia
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
| | - Andrey Kulbachinskiy
- Institute of Gene Biology, Russian Academy of Sciences, Moscow119334, Russia
- Institute of Molecular Genetics, National Research Center “Kurchatov Institute”, Moscow123182, Russia
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33
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Gao Z, Feng Y. Bacteriophage strategies for overcoming host antiviral immunity. Front Microbiol 2023; 14:1211793. [PMID: 37362940 PMCID: PMC10286901 DOI: 10.3389/fmicb.2023.1211793] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 05/17/2023] [Indexed: 06/28/2023] Open
Abstract
Phages and their bacterial hosts together constitute a vast and diverse ecosystem. Facing the infection of phages, prokaryotes have evolved a wide range of antiviral mechanisms, and phages in turn have adopted multiple tactics to circumvent or subvert these mechanisms to survive. An in-depth investigation into the interaction between phages and bacteria not only provides new insight into the ancient coevolutionary conflict between them but also produces precision biotechnological tools based on anti-phage systems. Moreover, a more complete understanding of their interaction is also critical for the phage-based antibacterial measures. Compared to the bacterial antiviral mechanisms, studies into counter-defense strategies adopted by phages have been a little slow, but have also achieved important advances in recent years. In this review, we highlight the numerous intracellular immune systems of bacteria as well as the countermeasures employed by phages, with an emphasis on the bacteriophage strategies in response to host antiviral immunity.
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Affiliation(s)
| | - Yue Feng
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
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Islam F, Purkait D, Mishra PP. Insights into the Dynamics and Helicase Activity of RecD2 of Deinococcus radiodurans during DNA Repair: A Single-Molecule Perspective. J Phys Chem B 2023; 127:4351-4363. [PMID: 37163679 DOI: 10.1021/acs.jpcb.3c00778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
While the double helix is the most stable conformation of DNA inside cells, its transient unwinding and subsequent partial separation of the two complementary strands yields an intermediate single-stranded DNA (ssDNA). The ssDNA is involved in all major DNA transactions such as replication, transcription, recombination, and repair. The process of DNA unwinding and translocation is shouldered by helicases that transduce the chemical energy derived from nucleotide triphosphate (NTP) hydrolysis to mechanical energy and utilize it to destabilize hydrogen bonds between complementary base pairs. Consequently, a comprehensive understanding of the molecular mechanisms of these enzymes is essential. In the last few decades, a combination of single-molecule techniques (force-based manipulation and visualization) have been employed to study helicase action. These approaches have allowed researchers to study the single helicase-DNA complex in real-time and the free energy landscape of their interaction together with the detection of conformational intermediates and molecular heterogeneity during the course of helicase action. Furthermore, the unique ability of these techniques to resolve helicase motion at nanometer and millisecond spatial and temporal resolutions, respectively, provided surprising insights into their mechanism of action. This perspective outlines the contribution of single-molecule methods in deciphering molecular details of helicase activities. It also exemplifies how each technique was or can be used to study the helicase action of RecD2 in recombination DNA repair.
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Affiliation(s)
- Farhana Islam
- Single Molecule Biophysics Lab, Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
- Homi Bhabha National Institute, Mumbai 400094, India
| | - Debayan Purkait
- Single Molecule Biophysics Lab, Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
- Homi Bhabha National Institute, Mumbai 400094, India
| | - Padmaja Prasad Mishra
- Single Molecule Biophysics Lab, Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
- Homi Bhabha National Institute, Mumbai 400094, India
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Cherry ME, Dubiel K, Henry C, Wood EA, Revitt-Mills SA, Keck JL, Cox MM, van Oijen AM, Ghodke H, Robinson A. Spatiotemporal Dynamics of Single-stranded DNA Intermediates in Escherichia coli. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539320. [PMID: 37214928 PMCID: PMC10197600 DOI: 10.1101/2023.05.08.539320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Single-stranded DNA gaps form within the E. coli chromosome during replication, repair and recombination. However, information about the extent of ssDNA creation in the genome is limited. To complement a recent whole-genome sequencing study revealing ssDNA gap genomic distribution, size, and frequency, we used fluorescence microscopy to monitor the spatiotemporal dynamics of single-stranded DNA within live E. coli cells. The ssDNA was marked by a functional fluorescent protein fusion of the SSB protein that replaces the wild type SSB. During log-phase growth the SSB fusion produces a mixture of punctate foci and diffuse fluorescence spread throughout the cytosol. Many foci are clustered. Fluorescent markers of DNA polymerase III frequently co-localize with SSB foci, often localizing to the outer edge of the large SSB features. Novel SSB-enriched features form and resolve regularly during normal growth. UV irradiation induces a rapid increase in SSB foci intensity and produces large features composed of multiple partially overlapping foci. The results provide a critical baseline for further exploration of ssDNA generation during DNA metabolism. Alterations in the patterns seen in a mutant lacking RecB function tentatively suggest associations of particular SSB features with the repair of double strand breaks and post-replication gaps.
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Chen X, Wolin SL. Transfer RNA halves are found as nicked tRNAs in cells: evidence that nicked tRNAs regulate expression of an RNA repair operon. RNA (NEW YORK, N.Y.) 2023; 29:620-629. [PMID: 36781286 PMCID: PMC10159003 DOI: 10.1261/rna.079575.122] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 02/01/2023] [Indexed: 05/06/2023]
Abstract
Transfer RNA fragments are proposed to regulate numerous processes in eukaryotes, including translation inhibition, epigenetic inheritance, and cancer. In the bacterium Salmonella enterica serovar Typhimurium, 5' tRNA halves ending in 2',3' cyclic phosphate are proposed to bind the RtcR transcriptional activator, resulting in transcription of an RNA repair operon. However, since 5' and 3' tRNA halves can remain base paired after cleavage, the 5' tRNA halves could potentially bind RtcR as nicked tRNAs. Here we report that nicked tRNAs are ligands for RtcR. By isolating RNA from bacteria under conditions that preserve base pairing, we show that many tRNA halves are in the form of nicked tRNAs. Using a circularly permuted tRNA that mimics a nicked tRNA, we show that nicked tRNA ending in 2',3' cyclic phosphate is a better ligand for RtcR than the corresponding 5' tRNA half. In human cells, we show that some tRNA halves similarly remain base paired as nicked tRNAs following cleavage by anticodon nucleases. Our work supports a role for the RNA repair operon in repairing nicked tRNAs and has implications for the functions proposed for tRNA fragments in eukaryotes.
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Affiliation(s)
- Xinguo Chen
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, USA
| | - Sandra L Wolin
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, USA
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Zhou K, Xue CX, Xu T, Shen P, Wei S, Wyres KL, Lam MMC, Liu J, Lin H, Chen Y, Holt KE, Xiao Y. A point mutation in recC associated with subclonal replacement of carbapenem-resistant Klebsiella pneumoniae ST11 in China. Nat Commun 2023; 14:2464. [PMID: 37117217 PMCID: PMC10147710 DOI: 10.1038/s41467-023-38061-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 04/13/2023] [Indexed: 04/30/2023] Open
Abstract
Adaptation to selective pressures is crucial for clinically important pathogens to establish epidemics, but the underlying evolutionary drivers remain poorly understood. The current epidemic of carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant threat to public health. In this study we analyzed the genome sequences of 794 CRKP bloodstream isolates collected in 40 hospitals in China between 2014 and 2019. We uncovered a subclonal replacement in the predominant clone ST11, where the previously prevalent subclone OL101:KL47 was replaced by O2v1:KL64 over time in a stepwise manner. O2v1:KL64 carried a higher load of mobile genetic elements, and a point mutation exclusively detected in the recC of O2v1:KL64 significantly promotes recombination proficiency. The epidemic success of O2v1:KL64 was further associated with a hypervirulent sublineage with enhanced resistance to phagocytosis, sulfamethoxazole-trimethoprim, and tetracycline. The phenotypic alterations were linked to the overrepresentation of hypervirulence determinants and antibiotic genes conferred by the acquisition of an rmpA-positive pLVPK-like virulence plasmid and an IncFII-type multidrug-resistant plasmid, respectively. The dissemination of the sublineage was further promoted by more frequent inter-hospital transmission. The results collectively demonstrate that the expansion of O2v1:KL64 is correlated to a repertoire of genomic alterations convergent in a subpopulation with evolutionary advantages.
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Affiliation(s)
- Kai Zhou
- Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital (Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China.
| | - Chun-Xu Xue
- Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital (Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China
| | - Tingting Xu
- Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital (Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China
| | - Ping Shen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Sha Wei
- Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital (Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China
| | - Kelly L Wyres
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, 3004, Australia
| | - Margaret M C Lam
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, 3004, Australia
| | - Jinquan Liu
- Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital (Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, China
| | - Haoyun Lin
- Department of Clinical Laboratory, Shenzhen People's Hospital, Shenzhen, China
| | - Yunbo Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Kathryn E Holt
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, 3004, Australia
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Yonghong Xiao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, National Medical Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
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CRISPR-Cas adaptation in Escherichia coli. Biosci Rep 2023; 43:232582. [PMID: 36809461 PMCID: PMC10011333 DOI: 10.1042/bsr20221198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 02/23/2023] Open
Abstract
Prokaryotes use the adaptive immunity mediated via the Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR associated (CRISPR-Cas) system for protection against invading elements such as phages and plasmids. The immunity is achieved by capturing small DNA fragments or spacers from foreign nucleic acids (protospacers) and integrating them into the host CRISPR locus. This step of CRISPR-Cas immunity called 'naïve CRISPR adaptation' requires the conserved Cas1-Cas2 complex and is often supported by variable host proteins that assist in spacer processing and integration. Bacteria that have acquired new spacers become immune to the same invading elements when reinfected. CRISPR-Cas immunity can also be updated by integrating new spacers from the same invading elements, a process called 'primed adaptation'. Only properly selected and integrated spacers are functional in the next steps of CRISPR immunity when their processed transcripts are used for RNA-guided target recognition and interference (target degradation). Capturing, trimming, and integrating new spacers in the correct orientation are universal steps of adaptation to all CRISPR-Cas systems, but some details are CRISPR-Cas type-specific and species-specific. In this review, we provide an overview of the mechanisms of CRISPR-Cas class 1 type I-E adaptation in Escherichia coli as a general model for adaptation processes (DNA capture and integration) that have been studied in detail. We focus on the role of host non-Cas proteins involved in adaptation, particularly on the role of homologous recombination.
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Zahradka K, Repar J, Đermić D, Zahradka D. Chromosome Segregation and Cell Division Defects in Escherichia coli Recombination Mutants Exposed to Different DNA-Damaging Treatments. Microorganisms 2023; 11:microorganisms11030701. [PMID: 36985274 PMCID: PMC10051365 DOI: 10.3390/microorganisms11030701] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 03/05/2023] [Indexed: 03/30/2023] Open
Abstract
Homologous recombination repairs potentially lethal DNA lesions such as double-strand DNA breaks (DSBs) and single-strand DNA gaps (SSGs). In Escherichia coli, DSB repair is initiated by the RecBCD enzyme that resects double-strand DNA ends and loads RecA recombinase to the emerging single-strand (ss) DNA tails. SSG repair is mediated by the RecFOR protein complex that loads RecA onto the ssDNA segment of gaped duplex. In both repair pathways, RecA catalyses reactions of homologous DNA pairing and strand exchange, while RuvABC complex and RecG helicase process recombination intermediates. In this work, we have characterised cytological changes in various recombination mutants of E. coli after three different DNA-damaging treatments: (i) expression of I-SceI endonuclease, (ii) γ-irradiation, and (iii) UV-irradiation. All three treatments caused severe chromosome segregation defects and DNA-less cell formation in the ruvABC, recG, and ruvABC recG mutants. After I-SceI expression and γ-irradiation, this phenotype was efficiently suppressed by the recB mutation, indicating that cytological defects result mostly from incomplete DSB repair. In UV-irradiated cells, the recB mutation abolished cytological defects of recG mutants and also partially suppressed the cytological defects of ruvABC recG mutants. However, neither recB nor recO mutation alone could suppress the cytological defects of UV-irradiated ruvABC mutants. The suppression was achieved only by simultaneous inactivation of the recB and recO genes. Cell survival and microscopic analysis suggest that chromosome segregation defects in UV-irradiated ruvABC mutants largely result from defective processing of stalled replication forks. The results of this study show that chromosome morphology is a valuable marker in genetic analyses of recombinational repair in E. coli.
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Affiliation(s)
- Ksenija Zahradka
- Laboratory for Molecular Microbiology, Division of Molecular Biology, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Jelena Repar
- Laboratory for Molecular Microbiology, Division of Molecular Biology, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Damir Đermić
- Laboratory for Molecular Microbiology, Division of Molecular Biology, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Davor Zahradka
- Laboratory for Molecular Microbiology, Division of Molecular Biology, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
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Amundsen SK, Richardson A, Ha K, Smith GR. A flexible RecC surface loop required for Chi hotspot control of RecBCD enzyme. Genetics 2023; 223:iyac175. [PMID: 36521180 PMCID: PMC9991510 DOI: 10.1093/genetics/iyac175] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/11/2022] [Accepted: 11/14/2022] [Indexed: 12/23/2022] Open
Abstract
Escherichia coli RecBCD helicase-nuclease promotes vital homologous recombination-based repair of DNA double-strand breaks. The RecB nuclease domain (Nuc) is connected to the RecB helicase domain by a 19-amino-acid tether. When DNA binds to RecBCD, published evidence suggests that Nuc moves ∼50 Å from the exit of a RecC tunnel, from which the 3'-ended strand emerges during unwinding, to a distant position on RecC's surface. During subsequent ATP-dependent unwinding of DNA, Nuc nicks the 3'-ended strand near 5'-GCTGGTGG-3' (Chi recombination hotspot). Here, we test our model of Nuc swinging on the tether from the RecC tunnel exit to the RecC distant surface and back to the RecC tunnel exit to cut at Chi. We identify positions in a flexible surface loop on RecC and on RecB Nuc with complementary charges, mutation of which strongly reduces but does not eliminate Chi hotspot activity in cells. The recC loop mutation interacts with recB mutations hypothesized to be in the Chi-activated intramolecular signal transduction pathway; the double mutants, but not the single mutants, eliminate Chi hotspot activity. A RecC amino acid near the flexible loop is also essential for full Chi activity; its alteration likewise synergizes with a signal transduction mutation to eliminate Chi activity. We infer that altering the RecC surface loop reduces coordination among the subunits, which is critical for Chi hotspot activity. We discuss other RecBCD mutants with related properties.
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Affiliation(s)
- Susan K Amundsen
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | | | - Khoi Ha
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Gerald R Smith
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
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Wang Y, Zhang X, Lin Y, Lin H. The electron transport mechanism of downflow Leersia hexandra Swartz constructed wetland-microbial fuel cell when used to treat Cr(VI) and p-chlorophenol. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:37929-37945. [PMID: 36576625 DOI: 10.1007/s11356-022-24872-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
Constructed wetland-microbial fuel cells are used to treat heavy metal and/or refractory organic wastewater. However, the electron transport mechanism of downflow Leersia hexandra constructed wetland-microbial fuel cells (DLCW-MFCs) is poorly understood when used to treat composite-polluted wastewater containing Cr(VI) and p-chlorophenol (4-CP) (C&P). In this study, metagenomics and in situ electrochemical techniques were used to investigate the electrochemical properties and the electricigens and their dominant gene functions. The DLCW-MFC was used to treat C&P and single-pollutant wastewater containing Cr(VI) (SC) and 4-CP (SP). The results showed that C&P had a higher current response and charge transfer capability and lower solution resistance plus charge transfer resistance. The anode bacteria solution of C&P contained more electron carriers (RF, FMN, FAD, CoQ10, and Cyt c). Metagenomic sequencing indicated that the total relative abundance of the microorganisms associated with electricity production (Desulfovibrio, Pseudomonas, Azospirillum, Nocardia, Microbacterium, Delftia, Geobacter, Acinetobacter, Bacillus, and Clostridium) was the highest in C&P (4.24%). However, Microbacterium was abundant in SP (0.12%), which exerted antagonistic effects on other electricigens. Among the 10 electricigens based on gene annotation, C&P had a higher overall relative abundance of the Unigene gene annotated to the KO pathway and CAZy level B compared with SC and SP, which were 1.31% and 0.582% respectively. Unigene153954 (ccmC), Unigene357497 (coxB), and Unigene1033667 (ubiG) were related to the electron carrier Cyt c, electron transfer, and CoQ biosynthesis, respectively. These were annotated to Desulfovibrio, Delftia, and Pseudomonas, respectively. Unigene161312 (AA1) used phenols and other substrates as electron donors and was annotated to Pseudomonas. Other functional carbohydrate enzyme genes (e.g., GT2, GT4, and GH31) used carbohydrates as donors and were annotated to other electricigens. This study provides a theoretical basis for electron transfer to promote the development of CW-MFCs.
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Affiliation(s)
- Yian Wang
- College of Environmental Science and Engineering, Guilin University of Technology, 319 Yanshan Street, Guilin, 541000, China
- Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 319 Yanshan Street, 541000, Guilin, China
| | - Xuehong Zhang
- College of Environmental Science and Engineering, Guilin University of Technology, 319 Yanshan Street, Guilin, 541000, China
- Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 319 Yanshan Street, 541000, Guilin, China
| | - Yi Lin
- College of Environmental Science and Engineering, Guilin University of Technology, 319 Yanshan Street, Guilin, 541000, China
- Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 319 Yanshan Street, 541000, Guilin, China
| | - Hua Lin
- College of Environmental Science and Engineering, Guilin University of Technology, 319 Yanshan Street, Guilin, 541000, China.
- Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 319 Yanshan Street, 541000, Guilin, China.
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Yang J, Sun Y, Wang Y, Hao W, Cheng K. Structural and DNA end resection study of the bacterial NurA-HerA complex. BMC Biol 2023; 21:42. [PMID: 36829173 PMCID: PMC9960219 DOI: 10.1186/s12915-023-01542-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 02/10/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND The nuclease NurA and the ATPase/translocase HerA play a vital role in repair of double-strand breaks (DSB) during the homologous recombination in archaea. A NurA-HerA complex is known to mediate DSB DNA end resection, leading to formation of a free 3' end used to search for the homologous sequence. Despite the structures of individual archaeal types of NurA and HerA having been reported, there is limited information regarding the molecular mechanisms underlying this process. Some bacteria also possess homologs of NurA and HerA; however, the bacterial type of this complex, as well as the detailed mechanisms underlying the joining of NurA-HerA in DSB DNA end resection, remains unclear. RESULTS We report for the first time the crystal structures of Deinococcus radiodurans HerA (drHerA) in the nucleotide-free and ADP-binding modes. A D. radiodurans NurA-HerA complex structure was constructed according to a low-resolution cryo-electron microscopy map. We performed site-directed mutagenesis to map the drNurA-HerA interaction sites, suggesting that their interaction is mainly mediated by ionic links, in contrast to previously characterized archaeal NurA-HerA interactions. The key residues responsible for the DNA translocation activity, DNA unwinding activity, and catalytic activities of the drNurA-HerA complex were identified. A HerA/FtsK-specific translocation-related motif (TR motif) that guarantees the processivity of double-stranded DNA (dsDNA) translocation was identified. Moreover, a mechanism for the translocation-regulated resection of the 5' tail of broken dsDNA and the corresponding generation of a recombinogenic 3' single-stranded DNA tail by the drNurA-HerA complex was elucidated. CONCLUSIONS Our work provides new insights into the mechanism underlying bacterial NurA-HerA-mediated DSB DNA end resection, and the way this complex digests the 5' tail of a DNA duplex and provides long 3' free end for strand invasion in the bacterial homologous recombination process.
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Affiliation(s)
- Jieyu Yang
- grid.410595.c0000 0001 2230 9154Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121 China
| | - Yiyang Sun
- grid.410595.c0000 0001 2230 9154Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121 China
| | - Ying Wang
- grid.410595.c0000 0001 2230 9154Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121 China
| | - Wanshan Hao
- grid.410595.c0000 0001 2230 9154Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121 China
| | - Kaiying Cheng
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, 311121, China. .,State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, China.
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Tang J, Brynildsen MP. Genome-wide mapping of fluoroquinolone-stabilized DNA gyrase cleavage sites displays drug specific effects that correlate with bacterial persistence. Nucleic Acids Res 2023; 51:1208-1228. [PMID: 36631985 PMCID: PMC9943676 DOI: 10.1093/nar/gkac1223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 12/03/2022] [Accepted: 12/12/2022] [Indexed: 01/13/2023] Open
Abstract
Bacterial persisters are rare phenotypic variants that are suspected to be culprits of recurrent infections. Fluoroquinolones (FQs) are a class of antibiotics that facilitate bacterial killing by stabilizing bacterial type II topoisomerases when they are in a complex with cleaved DNA. In Escherichia coli, DNA gyrase is the primary FQ target, and previous work has demonstrated that persisters are not spared from FQ-induced DNA damage. Since DNA gyrase cleavage sites (GCSs) largely govern the sites of DNA damage from FQ treatment, we hypothesized that GCS characteristics (e.g. number, strength, location) may influence persistence. To test this hypothesis, we measured genome-wide GCS distributions after treatment with a panel of FQs in stationary-phase cultures. We found drug-specific effects on the GCS distribution and discovered a strong negative correlation between the genomic cleavage strength and FQ persister levels. Further experiments and analyses suggested that persistence was unlikely to be governed by cleavage to individual sites, but rather survival was a function of the genomic GCS distribution. Together, these findings demonstrate FQ-specific differences in GCS distribution that correlate with persister levels and suggest that FQs that better stabilize DNA gyrase in cleaved complexes with DNA will lead to lower levels of persistence.
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Affiliation(s)
- Juechun Tang
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
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44
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Structural Studies of Pif1 Helicases from Thermophilic Bacteria. Microorganisms 2023; 11:microorganisms11020479. [PMID: 36838444 PMCID: PMC9964779 DOI: 10.3390/microorganisms11020479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/03/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
Pif1 proteins are DNA helicases belonging to Superfamily 1, with 5' to 3' directionality. They are conserved from bacteria to human and have been shown to be particularly important in eukaryotes for replication and nuclear and mitochondrial genome stability. However, Pif1 functions in bacteria are less known. While most Pif1 from mesophilic bacteria consist of the helicase core with limited N-terminal and C-terminal extensions, some Pif1 from thermophilic bacteria exhibit a C-terminal WYL domain. We solved the crystal structures of Pif1 helicase cores from thermophilic bacteria Deferribacter desulfuricans and Sulfurihydrogenibium sp. in apo and nucleotide bound form. We show that the N-terminal part is important for ligand binding. The full-length Pif1 helicase was predicted based on the Alphafold algorithm and the nucleic acid binding on the Pif1 helicase core and the WYL domain was modelled based on known crystallographic structures. The model predicts that amino acids in the domains 1A, WYL, and linker between the Helicase core and WYL are important for nucleic acid binding. Therefore, the N-terminal and C-terminal extensions may be necessary to strengthen the binding of nucleic acid on these Pif1 helicases. This may be an adaptation to thermophilic conditions.
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Teoh CP, Lavin P, Yusof NA, González-Aravena M, Najimudin N, Cheah YK, Wong CMVL. Transcriptomics analysis provides insights into the heat adaptation strategies of an Antarctic bacterium, Cryobacterium sp. SO1. Polar Biol 2023. [DOI: 10.1007/s00300-023-03115-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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Gao J, Liu H, Zhang Z, Liang Z. Establishment, optimization, and application of genetic technology in Aspergillus spp. Front Microbiol 2023; 14:1141869. [PMID: 37025635 PMCID: PMC10071863 DOI: 10.3389/fmicb.2023.1141869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/27/2023] [Indexed: 04/08/2023] Open
Abstract
Aspergillus is widely distributed in nature and occupies a crucial ecological niche, which has complex and diverse metabolic pathways and can produce a variety of metabolites. With the deepening of genomics exploration, more Aspergillus genomic informations have been elucidated, which not only help us understand the basic mechanism of various life activities, but also further realize the ideal functional transformation. Available genetic engineering tools include homologous recombinant systems, specific nuclease based systems, and RNA techniques, combined with transformation methods, and screening based on selective labeling. Precise editing of target genes can not only prevent and control the production of mycotoxin pollutants, but also realize the construction of economical and efficient fungal cell factories. This paper reviewed the establishment and optimization process of genome technologies, hoping to provide the theoretical basis of experiments, and summarized the recent progress and application in genetic technology, analyzes the challenges and the possibility of future development with regard to Aspergillus.
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Affiliation(s)
- Jing Gao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Huiqing Liu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Zhenzhen Zhang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Zhihong Liang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
- The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing, China
- Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
- *Correspondence: Zhihong Liang,
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Bartolo-Aguilar Y, Chávez-Cabrera C, Flores-Cotera LB, Badillo-Corona JA, Oliver-Salvador C, Marsch R. The potential of cold-shock promoters for the expression of recombinant proteins in microbes and mammalian cells. J Genet Eng Biotechnol 2022; 20:173. [PMID: 36580173 PMCID: PMC9800685 DOI: 10.1186/s43141-022-00455-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 12/15/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Low-temperature expression of recombinant proteins may be advantageous to support their proper folding and preserve bioactivity. The generation of expression vectors regulated under cold conditions can improve the expression of some target proteins that are difficult to express in different expression systems. The cspA encodes the major cold-shock protein from Escherichia coli (CspA). The promoter of cspA has been widely used to develop cold shock-inducible expression platforms in E. coli. Moreover, it is often necessary to employ expression systems other than bacteria, particularly when recombinant proteins require complex post-translational modifications. Currently, there are no commercial platforms available for expressing target genes by cold shock in eukaryotic cells. Consequently, genetic elements that respond to cold shock offer the possibility of developing novel cold-inducible expression platforms, particularly suitable for yeasts, and mammalian cells. CONCLUSIONS This review covers the importance of the cellular response to low temperatures and the prospective use of cold-sensitive promoters to direct the expression of recombinant proteins. This concept may contribute to renewing interest in applying white technologies to produce recombinant proteins that are difficult to express.
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Affiliation(s)
- Yaneth Bartolo-Aguilar
- Department of Biotechnology and Bioengineering, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360, Mexico City, Mexico
- Instituto Politécnico Nacional-Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto s/n, Colonia Barrio La Laguna Ticomán, 07340, Mexico City, Mexico
| | - Cipriano Chávez-Cabrera
- Colegio de Estudios Científicos y Tecnológicos del Estado de Michoacán, CECyTE Michoacán, Héroes de la Revolución S/N, Col. Centro, 61880, Churumuco de Morelos, Michoacán, Mexico.
| | - Luis Bernardo Flores-Cotera
- Department of Biotechnology and Bioengineering, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360, Mexico City, Mexico
| | - Jesús Agustín Badillo-Corona
- Instituto Politécnico Nacional-Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto s/n, Colonia Barrio La Laguna Ticomán, 07340, Mexico City, Mexico
| | - Carmen Oliver-Salvador
- Instituto Politécnico Nacional-Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto s/n, Colonia Barrio La Laguna Ticomán, 07340, Mexico City, Mexico
| | - Rodolfo Marsch
- Department of Biotechnology and Bioengineering, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360, Mexico City, Mexico
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Wilkinson M, Wilkinson OJ, Feyerherm C, Fletcher EE, Wigley DB, Dillingham MS. Structures of RecBCD in complex with phage-encoded inhibitor proteins reveal distinctive strategies for evasion of a bacterial immunity hub. eLife 2022; 11:e83409. [PMID: 36533901 PMCID: PMC9836394 DOI: 10.7554/elife.83409] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 12/18/2022] [Indexed: 12/23/2022] Open
Abstract
Following infection of bacterial cells, bacteriophage modulate double-stranded DNA break repair pathways to protect themselves from host immunity systems and prioritise their own recombinases. Here, we present biochemical and structural analysis of two phage proteins, gp5.9 and Abc2, which target the DNA break resection complex RecBCD. These exemplify two contrasting mechanisms for control of DNA break repair in which the RecBCD complex is either inhibited or co-opted for the benefit of the invading phage. Gp5.9 completely inhibits RecBCD by preventing it from binding to DNA. The RecBCD-gp5.9 structure shows that gp5.9 acts by substrate mimicry, binding predominantly to the RecB arm domain and competing sterically for the DNA binding site. Gp5.9 adopts a parallel coiled-coil architecture that is unprecedented for a natural DNA mimic protein. In contrast, binding of Abc2 does not substantially affect the biochemical activities of isolated RecBCD. The RecBCD-Abc2 structure shows that Abc2 binds to the Chi-recognition domains of the RecC subunit in a position that might enable it to mediate the loading of phage recombinases onto its single-stranded DNA products.
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Affiliation(s)
- Martin Wilkinson
- Section of Structural Biology, Department of Infectious Disease, Faculty of Medicine, Imperial College LondonLondonUnited Kingdom
| | - Oliver J Wilkinson
- DNA:protein Interactions Unit, School of Biochemistry, University of BristolBristolUnited Kingdom
| | - Connie Feyerherm
- DNA:protein Interactions Unit, School of Biochemistry, University of BristolBristolUnited Kingdom
| | - Emma E Fletcher
- DNA:protein Interactions Unit, School of Biochemistry, University of BristolBristolUnited Kingdom
| | - Dale B Wigley
- Section of Structural Biology, Department of Infectious Disease, Faculty of Medicine, Imperial College LondonLondonUnited Kingdom
| | - Mark S Dillingham
- DNA:protein Interactions Unit, School of Biochemistry, University of BristolBristolUnited Kingdom
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McKenzie AM, Henry C, Myers KS, Place MM, Keck JL. Identification of genetic interactions with priB links the PriA/PriB DNA replication restart pathway to double-strand DNA break repair in Escherichia coli. G3 (BETHESDA, MD.) 2022; 12:jkac295. [PMID: 36326440 PMCID: PMC9713433 DOI: 10.1093/g3journal/jkac295] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 10/20/2022] [Indexed: 11/30/2023]
Abstract
Collisions between DNA replication complexes (replisomes) and impediments such as damaged DNA or proteins tightly bound to the chromosome lead to premature dissociation of replisomes at least once per cell cycle in Escherichia coli. Left unrepaired, these events produce incompletely replicated chromosomes that cannot be properly partitioned into daughter cells. DNA replication restart, the process that reloads replisomes at prematurely terminated sites, is therefore essential in E. coli and other bacteria. Three replication restart pathways have been identified in E. coli: PriA/PriB, PriA/PriC, and PriC/Rep. A limited number of genetic interactions between replication restart and other genome maintenance pathways have been defined, but a systematic study placing replication restart reactions in a broader cellular context has not been performed. We have utilized transposon-insertion sequencing to identify new genetic interactions between DNA replication restart pathways and other cellular systems. Known genetic interactors with the priB replication restart gene (uniquely involved in the PriA/PriB pathway) were confirmed and several novel priB interactions were discovered. Targeted genetic and imaging-based experiments with priB and its genetic partners revealed significant double-strand DNA break accumulation in strains with mutations in dam, rep, rdgC, lexA, or polA. Modulating the activity of the RecA recombinase partially suppressed the detrimental effects of rdgC or lexA mutations in ΔpriB cells. Taken together, our results highlight roles for several genes in double-strand DNA break homeostasis and define a genetic network that facilitates DNA repair/processing upstream of PriA/PriB-mediated DNA replication restart in E. coli.
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Affiliation(s)
- Aidan M McKenzie
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Camille Henry
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Kevin S Myers
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - Michael M Place
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53726, USA
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
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Nethery MA, Hidalgo-Cantabrana C, Roberts A, Barrangou R. CRISPR-based engineering of phages for in situ bacterial base editing. Proc Natl Acad Sci U S A 2022; 119:e2206744119. [PMID: 36343261 PMCID: PMC9674246 DOI: 10.1073/pnas.2206744119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 10/14/2022] [Indexed: 09/29/2023] Open
Abstract
Investigation of microbial gene function is essential to the elucidation of ecological roles and complex genetic interactions that take place in microbial communities. While microbiome studies have increased in prevalence, the lack of viable in situ editing strategies impedes experimental progress, rendering genetic knowledge and manipulation of microbial communities largely inaccessible. Here, we demonstrate the utility of phage-delivered CRISPR-Cas payloads to perform targeted genetic manipulation within a community context, deploying a fabricated ecosystem (EcoFAB) as an analog for the soil microbiome. First, we detail the engineering of two classical phages for community editing using recombination to replace nonessential genes through Cas9-based selection. We show efficient engineering of T7, then demonstrate the expression of antibiotic resistance and fluorescent genes from an engineered λ prophage within an Escherichia coli host. Next, we modify λ to express an APOBEC-1-based cytosine base editor (CBE), which we leverage to perform C-to-T point mutations guided by a modified Cas9 containing only a single active nucleolytic domain (nCas9). We strategically introduce these base substitutions to create premature stop codons in-frame, inactivating both chromosomal (lacZ) and plasmid-encoded genes (mCherry and ampicillin resistance) without perturbation of the surrounding genomic regions. Furthermore, using a multigenera synthetic soil community, we employ phage-assisted base editing to induce host-specific phenotypic alterations in a community context both in vitro and within the EcoFAB, observing editing efficiencies from 10 to 28% across the bacterial population. The concurrent use of a synthetic microbial community, soil matrix, and EcoFAB device provides a controlled and reproducible model to more closely approximate in situ editing of the soil microbiome.
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Affiliation(s)
- Matthew A. Nethery
- Genomic Sciences Graduate Program, North Carolina State University, Raleigh, NC 27695
- Department of Food, Bioprocessing & Nutrition Sciences, North Carolina State University, Raleigh, NC 27606
| | - Claudio Hidalgo-Cantabrana
- Department of Food, Bioprocessing & Nutrition Sciences, North Carolina State University, Raleigh, NC 27606
| | - Avery Roberts
- Genomic Sciences Graduate Program, North Carolina State University, Raleigh, NC 27695
- Department of Food, Bioprocessing & Nutrition Sciences, North Carolina State University, Raleigh, NC 27606
| | - Rodolphe Barrangou
- Genomic Sciences Graduate Program, North Carolina State University, Raleigh, NC 27695
- Department of Food, Bioprocessing & Nutrition Sciences, North Carolina State University, Raleigh, NC 27606
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