1
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Matlock W, Shaw LP, Sheppard SK, Feil E. Towards quantifying plasmid similarity. Microb Genom 2024; 10:001290. [PMID: 39264704 PMCID: PMC11392043 DOI: 10.1099/mgen.0.001290] [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: 05/24/2024] [Accepted: 08/01/2024] [Indexed: 09/13/2024] Open
Abstract
Plasmids are extrachromosomal replicons which can quickly spread resistance and virulence genes between clinical pathogens. From the tens of thousands of currently available plasmid sequences we know that overall plasmid diversity is structured, with related plasmids sharing a largely conserved 'backbone' of genes while being able to carry very different genetic cargo. Moreover, plasmid genomes can be structurally plastic and undergo frequent rearrangements. So, how can we quantify plasmid similarity? Answering this question requires practical efforts to sample natural variation as well as theoretical considerations of what defines a group of related plasmids. Here we consider the challenges of analysing and rationalising the current plasmid data deluge to define appropriate similarity thresholds.
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Affiliation(s)
- William Matlock
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Liam P. Shaw
- Department of Biology, University of Oxford, Oxford, UK
| | | | - Edward Feil
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, Bath, UK
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2
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Algarni S, Foley SL, Tang H, Zhao S, Gudeta DD, Khajanchi BK, Ricke SC, Han J. Development of an antimicrobial resistance plasmid transfer gene database for enteric bacteria. FRONTIERS IN BIOINFORMATICS 2023; 3:1279359. [PMID: 38033626 PMCID: PMC10682676 DOI: 10.3389/fbinf.2023.1279359] [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: 08/17/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Introduction: Type IV secretion systems (T4SSs) are integral parts of the conjugation process in enteric bacteria. These secretion systems are encoded within the transfer (tra) regions of plasmids, including those that harbor antimicrobial resistance (AMR) genes. The conjugal transfer of resistance plasmids can lead to the dissemination of AMR among bacterial populations. Methods: To facilitate the analyses of the conjugation-associated genes, transfer related genes associated with key groups of AMR plasmids were identified, extracted from GenBank and used to generate a plasmid transfer gene dataset that is part of the Virulence and Plasmid Transfer Factor Database at FDA, serving as the foundation for computational tools for the comparison of the conjugal transfer genes. To assess the genetic feature of the transfer gene database, genes/proteins of the same name (e.g., traI/TraI) or predicted function (VirD4 ATPase homologs) were compared across the different plasmid types to assess sequence diversity. Two analyses tools, the Plasmid Transfer Factor Profile Assessment and Plasmid Transfer Factor Comparison tools, were developed to evaluate the transfer genes located on plasmids and to facilitate the comparison of plasmids from multiple sequence files. To assess the database and associated tools, plasmid, and whole genome sequencing (WGS) data were extracted from GenBank and previous WGS experiments in our lab and assessed using the analysis tools. Results: Overall, the plasmid transfer database and associated tools proved to be very useful for evaluating the different plasmid types, their association with T4SSs, and increased our understanding how conjugative plasmids contribute to the dissemination of AMR genes.
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Affiliation(s)
- Suad Algarni
- Division of Microbiology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States
- Cellular and Molecular Biology Graduate Program, University of Arkansas, Fayetteville, AR, United States
| | - Steven L. Foley
- Division of Microbiology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States
| | - Hailin Tang
- Division of Bioinformatics and Biostatistics, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States
| | - Shaohua Zhao
- Office of Applied Science, Center for Veterinary Medicine, Food and Drug Administration, Laurel, MD, United States
| | - Dereje D. Gudeta
- Division of Microbiology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States
| | - Bijay K. Khajanchi
- Division of Microbiology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States
| | - Steven C. Ricke
- Meat Science and Animal Biologics Discovery Program, Animal and Dairy Sciences Department, University of Wisconsin, Madison, WI, United States
| | - Jing Han
- Division of Microbiology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, United States
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3
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Heo S, Oh SE, Lee G, Lee J, Ha NC, Jeon CO, Jeong K, Lee JH, Jeong DW. Staphylococcus equorum plasmid pKS1030-3 encodes auxiliary biofilm formation and trans-acting gene mobilization systems. Sci Rep 2023; 13:11108. [PMID: 37429971 DOI: 10.1038/s41598-023-38274-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 07/06/2023] [Indexed: 07/12/2023] Open
Abstract
The foodborne bacterium Staphylococcus equorum strain KS1030 harbours plasmid pSELNU1, which encodes a lincomycin resistance gene. pSELNU1 undergoes horizontal transfer between bacterial strains, thus spreading antibiotic resistance. However, the genes required for horizontal plasmid transfer are not encoded in pSELNU1. Interestingly, a relaxase gene, a type of gene related to horizontal plasmid transfer, is encoded in another plasmid of S. equorum KS1030, pKS1030-3. The complete genome of pKS1030-3 is 13,583 bp long and encodes genes for plasmid replication, biofilm formation (the ica operon), and horizontal gene transfer. The replication system of pKS1030-3 possesses the replication protein-encoding gene repB, a double-stranded origin of replication, and two single-stranded origins of replication. The ica operon, relaxase gene, and a mobilization protein-encoding gene were detected in pKS1030-3 strain-specifically. When expressed in S. aureus RN4220, the ica operon and relaxase operon of pKS1030-3 conferred biofilm formation ability and horizontal gene transfer ability, respectively. The results of our analyses show that the horizontal transfer of pSELNU1 of S. equorum strain KS1030 depends on the relaxase encoded by pKS1030-3, which is therefore trans-acting. Genes encoded in pKS1030-3 contribute to important strain-specific properties of S. equorum KS1030. These results could contribute to preventing the horizontal transfer of antibiotic resistance genes in food.
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Affiliation(s)
- Sojeong Heo
- Department of Food and Nutrition, Dongduk Women's University, Seoul, 02748, Republic of Korea
| | - Seung-Eun Oh
- Department of Food and Nutrition, Dongduk Women's University, Seoul, 02748, Republic of Korea
| | - Gawon Lee
- Department of Food and Nutrition, Dongduk Women's University, Seoul, 02748, Republic of Korea
| | - Jinwook Lee
- Research Institute of Agriculture and Life Sciences, Center for Food and Bioconvergence, Department of Agricultural Biotechnology, CALS, Seoul National University, Seoul, 08826, Republic of Korea
| | - Nam-Chul Ha
- Research Institute of Agriculture and Life Sciences, Center for Food and Bioconvergence, Department of Agricultural Biotechnology, CALS, Seoul National University, Seoul, 08826, Republic of Korea
| | - Che Ok Jeon
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Keuncheol Jeong
- Department of Food Science and Biotechnology, Kyonggi University, Suwon, 16227, Republic of Korea
| | - Jong-Hoon Lee
- Department of Food Science and Biotechnology, Kyonggi University, Suwon, 16227, Republic of Korea
| | - Do-Won Jeong
- Department of Food and Nutrition, Dongduk Women's University, Seoul, 02748, Republic of Korea.
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4
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Pons MC, Praud K, Da Re S, Cloeckaert A, Doublet B. Conjugative IncC Plasmid Entry Triggers the SOS Response and Promotes Effective Transfer of the Integrative Antibiotic Resistance Element SGI1. Microbiol Spectr 2023; 11:e0220122. [PMID: 36472437 PMCID: PMC9927553 DOI: 10.1128/spectrum.02201-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
The broad-host-range IncC plasmid family and the integrative mobilizable Salmonella genomic island 1 (SGI1) and its derivatives enable the spread of medically important antibiotic resistance genes among Gram-negative pathogens. Although several aspects of the complex functional interactions between IncC plasmids and SGI1 have been recently deciphered regarding their conjugative transfer and incompatibility, the biological signal resulting in the hijacking of the conjugative plasmid by the integrative mobilizable element remains unknown. Here, we demonstrate that the conjugative entry of IncC/IncA plasmids is detected at an early stage by SGI1 through the transient activation of the SOS response, which induces the expression of the SGI1 master activators SgaDC, shown to play a crucial role in the complex biology between SGI1 and IncC plasmids. Besides, we developed an original tripartite conjugation approach to directly monitor SGI1 mobilization in a time-dependent manner following conjugative entry of IncC plasmids. Finally, we propose an updated biological model of the conjugative mobilization of the chromosomal resistance element SGI1 by IncC plasmids. IMPORTANCE Antimicrobial resistance has become a major public health issue, particularly with the increase of multidrug resistance (MDR) in both animal and human pathogenic bacteria and with the emergence of resistance to medically important antibiotics. The spread between bacteria of successful mobile genetic elements, such as conjugative plasmids and integrative elements conferring multidrug resistance, is the main driving force in the dissemination of acquired antibiotic resistances among Gram-negative bacteria. Broad-host-range IncC plasmids and their integrative mobilizable SGI1 counterparts contribute to the spread of critically important resistance genes (e.g., extended-spectrum β-lactamases [ESBLs] and carbapenemases). A better knowledge of the complex biology of these broad-host-range mobile elements will help us to understand the dissemination of antimicrobial resistance genes that occurred across Gammaproteobacteria borders.
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Affiliation(s)
| | - Karine Praud
- INRAE, Université de Tours, ISP, Nouzilly, France
| | - Sandra Da Re
- INSERM, Université de Limoges, CHU de Limoges, RESINFIT, Limoges, France
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5
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Martinez-Vaz BM, Dodge AG, Lucero RM, Stockbridge RB, Robinson AA, Tassoulas LJ, Wackett LP. Wastewater bacteria remediating the pharmaceutical metformin: Genomes, plasmids and products. Front Bioeng Biotechnol 2022; 10:1086261. [PMID: 36588930 PMCID: PMC9800807 DOI: 10.3389/fbioe.2022.1086261] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022] Open
Abstract
Metformin is used globally to treat type II diabetes, has demonstrated anti-ageing and COVID mitigation effects and is a major anthropogenic pollutant to be bioremediated by wastewater treatment plants (WWTPs). Metformin is not adsorbed well by activated carbon and toxic N-chloro derivatives can form in chlorinated water. Most earlier studies on metformin biodegradation have used wastewater consortia and details of the genomes, relevant genes, metabolic products, and potential for horizontal gene transfer are lacking. Here, two metformin-biodegrading bacteria from a WWTP were isolated and their biodegradation characterized. Aminobacter sp. MET metabolized metformin stoichiometrically to guanylurea, an intermediate known to accumulate in some environments including WWTPs. Pseudomonas mendocina MET completely metabolized metformin and utilized all the nitrogen atoms for growth. Pseudomonas mendocina MET also metabolized metformin breakdown products sometimes observed in WWTPs: 1-N-methylbiguanide, biguanide, guanylurea, and guanidine. The genome of each bacterium was obtained. Genes involved in the transport of guanylurea in Aminobacter sp. MET were expressed heterologously and shown to serve as an antiporter to expel the toxic guanidinium compound. A novel guanylurea hydrolase enzyme was identified in Pseudomonas mendocina MET, purified, and characterized. The Aminobacter and Pseudomonas each contained one plasmid of 160 kb and 90 kb, respectively. In total, these studies are significant for the bioremediation of a major pollutant in WWTPs today.
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Affiliation(s)
- Betsy M. Martinez-Vaz
- Department of Biology and Biochemistry Program, Hamline University, St. Paul, MN, United States
| | - Anthony G. Dodge
- Department of Biochemistry, Molecular Biology and Biophysics and BioTechnology Institute, University of Minnesota, St. Paul, MN, United States
| | - Rachael M. Lucero
- Program in Chemical Biology and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Randy B. Stockbridge
- Program in Chemical Biology and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Ashley A. Robinson
- Department of Biology and Biochemistry Program, Hamline University, St. Paul, MN, United States
| | - Lambros J. Tassoulas
- Department of Biochemistry, Molecular Biology and Biophysics and BioTechnology Institute, University of Minnesota, St. Paul, MN, United States
| | - Lawrence P. Wackett
- Department of Biochemistry, Molecular Biology and Biophysics and BioTechnology Institute, University of Minnesota, St. Paul, MN, United States
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6
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Zhang F, Ye X, Yin Z, Hu M, Wang B, Liu W, Li B, Ren H, Jin Y, Yue J. Comparative genomics reveals new insights into the evolution of the IncA and IncC family of plasmids. Front Microbiol 2022; 13:1045314. [PMID: 36466664 PMCID: PMC9709138 DOI: 10.3389/fmicb.2022.1045314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/24/2022] [Indexed: 06/13/2024] Open
Abstract
Incompatibility groups IncA and IncC plasmids are of great concern due to their ability to disseminate antibiotic resistance in bacteria via conjugative transfer. A deep understanding of their genomic structures and evolutionary characteristics is of great significance for improving our knowledge about its multidrug-resistance evolution and dissemination. However, current knowledge of their backbone structure, features of core functional modules and the characteristics of variable regions is based on a few plasmids, which highlights the need for a comprehensive systematic study. The present study thoroughly compared and analysed 678 IncA and IncC plasmid genomes. We found that their core functional genes were occasionally deficient and sometimes existed as multiple functional copies/multiple families, which resulted in much diversity. The phylogeny of 13 core functional genes corresponded well to the plasmid subtypes. The conjugative transfer system gained diverse complexity and exhibited many previously unnoticed types with multiple combinations. The insertion of mobile genetic elements (MGEs) in plasmids varied between types and was present in 4 insertion spots in different types of plasmids with certain types of transposons, integrons and insertion sequences. The impact of gene duplication, deletion, the insertion of MGEs, genome rearrangement and recombination resulted in the complex dynamic variable backbone of IncA and IncC plasmids. And IncA and IncC plasmids were more complex than their closest relative SXT/R391 integrative conjugative elements (ICEs), which included nearly all of the diversity of SXT/R391 in key systems. Our work demonstrated a global and systematic view of the IncA and IncC plasmids and provides many new insights into their genome evolution.
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Affiliation(s)
- Fengwei Zhang
- Medical College of Guizhou University, Guiyang, China
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Xianwei Ye
- Medical College of Guizhou University, Guiyang, China
- Guizhou Provincial People’s Hospital, Guiyang, China
| | - Zhiqiu Yin
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Tai’an, China
| | - Mingda Hu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Boqian Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Wenting Liu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Beiping Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Hongguang Ren
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Yuan Jin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Junjie Yue
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
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7
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Nagy I, Szabó M, Hegyi A, Kiss J. Salmonella Genomic Island 1 requires a self-encoded small RNA for mobilization. Mol Microbiol 2021; 116:1533-1551. [PMID: 34784078 PMCID: PMC9299015 DOI: 10.1111/mmi.14846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 10/08/2021] [Accepted: 11/13/2021] [Indexed: 11/29/2022]
Abstract
The SGI1-family elements that are specifically mobilized by the IncA- and IncC-family plasmids are important vehicles of antibiotic resistance among enteric bacteria. Although SGI1 exploits many plasmid-derived conjugation and regulatory functions, the basic mobilization module of the island is unrelated to that of IncC plasmids. This module contains the oriT and encodes the mobilization proteins MpsA and MpsB, which belong to the tyrosine recombinases and not to relaxases. Here we report an additional, essential transfer factor of SGI1. This is a small RNA deriving from the 3'-end of a primary RNA that can also serve as mRNA of ORF S022. The functional domain of this sRNA named sgm-sRNA is encoded between the mpsA gene and the oriT of SGI1. Terminator-like sequence near the promoter of the primary transcript possibly has a regulatory function in controlling the amount of full-length primary RNA, which is converted to the active sgm-sRNA through consecutive maturation steps influenced by the 5'-end of the primary RNA. The mobilization module of SGI1 seems unique due to its atypical relaxase and the newly identified sgm-sRNA, which is required for the horizontal transfer of the island but appears to act differently from classical regulatory sRNAs.
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Affiliation(s)
- István Nagy
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - Mónika Szabó
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - Anna Hegyi
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - János Kiss
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
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8
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Durand R, Huguet KT, Rivard N, Carraro N, Rodrigue S, Burrus V. Crucial role of Salmonella genomic island 1 master activator in the parasitism of IncC plasmids. Nucleic Acids Res 2021; 49:7807-7824. [PMID: 33834206 PMCID: PMC8373056 DOI: 10.1093/nar/gkab204] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 03/09/2021] [Accepted: 03/15/2021] [Indexed: 12/26/2022] Open
Abstract
IncC conjugative plasmids and the multiple variants of Salmonella Genomic Island 1 (SGI1) are two functionally interacting families of mobile genetic elements commonly associated with multidrug resistance in the Gammaproteobacteria. SGI1 and its siblings are specifically mobilised in trans by IncC conjugative plasmids. Conjugative transfer of IncC plasmids is activated by the plasmid-encoded master activator AcaCD. SGI1 carries five AcaCD-responsive promoters that drive the expression of genes involved in its excision, replication, and mobilisation. SGI1 encodes an AcaCD homologue, the transcriptional activator complex SgaCD (also known as FlhDCSGI1) that seems to recognise and activate the same SGI1 promoters. Here, we investigated the relevance of SgaCD in SGI1's lifecycle. Mating assays revealed the requirement for SgaCD and its IncC-encoded counterpart AcaCD in the mobilisation of SGI1. An integrative approach combining ChIP-exo, Cappable-seq, and RNA-seq confirmed that SgaCD activates each of the 18 AcaCD-responsive promoters driving the expression of the plasmid transfer functions. A comprehensive analysis of the activity of the complete set of AcaCD-responsive promoters of SGI1 and the helper IncC plasmid was performed through reporter assays. qPCR and flow cytometry assays revealed that SgaCD is essential to elicit the excision and replication of SGI1 and destabilise the helper IncC plasmid.
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Affiliation(s)
- Romain Durand
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
| | - Kévin T Huguet
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
| | - Nicolas Rivard
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
| | - Nicolas Carraro
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
| | - Sébastien Rodrigue
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
| | - Vincent Burrus
- Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
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9
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Hancock SJ, Phan MD, Roberts LW, Vu TNM, Harris PNA, Beatson SA, Schembri MA. Characterization of DtrJ as an IncC plasmid conjugative DNA transfer component. Mol Microbiol 2021; 116:154-167. [PMID: 33567150 DOI: 10.1111/mmi.14697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 02/08/2021] [Indexed: 11/30/2022]
Abstract
Incompatibility group C (IncC) plasmids are large (50-400 kb), broad host range plasmids that drive the spread of genes conferring resistance to all classes of antibiotics, most notably the blaNDM gene that confers resistance to last-line carbapenems and the mcr-3 gene that confers resistance to colistin. Several recent studies have improved our understanding of the basic biological mechanisms driving the success of IncC, in particular the identification of multiple novel IncC conjugation genes by transposon directed insertion-site sequencing. Here, one of these genes, dtrJ, was examined in further detail. The dtrJ gene is located in the DNA transfer locus on the IncC backbone, and quantitative reverse-transcriptase PCR analysis revealed it is transcribed in the same operon as the DNA transfer genes traI and traD (encoding the relaxase and coupling protein, respectively) and activated by the AcaDC regulatory complex. We confirmed that DtrJ is not required for pilus biogenesis or mate pair formation. Instead, DtrJ localizes to the membrane, where it interacts with the coupling protein TraD and functions as an IncC DNA transfer protein. Overall, this work has defined the role of DtrJ in DNA transfer of IncC plasmids during conjugation.
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Affiliation(s)
- Steven J Hancock
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Minh-Duy Phan
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Leah W Roberts
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Thu Ngoc Minh Vu
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD, Australia.,College of Agriculture, Can Tho University, Can Tho City, Vietnam
| | - Patrick N A Harris
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia.,The University of Queensland Centre for Clinical Research, Brisbane, QLD, Australia
| | - Scott A Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
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10
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Hancock SJ, Phan MD, Luo Z, Lo AW, Peters KM, Nhu NTK, Forde BM, Whitfield J, Yang J, Strugnell RA, Paterson DL, Walsh TR, Kobe B, Beatson SA, Schembri MA. Comprehensive analysis of IncC plasmid conjugation identifies a crucial role for the transcriptional regulator AcaB. Nat Microbiol 2020; 5:1340-1348. [PMID: 32807890 DOI: 10.1038/s41564-020-0775-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 07/16/2020] [Indexed: 01/05/2023]
Abstract
The IncC family of broad-host-range plasmids enables the spread of antibiotic resistance genes among human enteric pathogens1-3. Although aspects of IncC plasmid conjugation have been well studied4-9, many roles of conjugation genes have been assigned based solely on sequence similarity. We applied hypersaturated transposon mutagenesis and transposon-directed insertion-site sequencing to determine the set of genes required for IncC conjugation. We identified 27 conjugation genes, comprising 19 that were previously identified (including two regulatory genes, acaDC) and eight not previously associated with conjugation. We show that one previously unknown gene, acaB, encodes a transcriptional regulator that has a crucial role in the regulation of IncC conjugation. AcaB binds upstream of the acaDC promoter to increase acaDC transcription; in turn, AcaDC activates the transcription of IncC conjugation genes. We solved the crystal structure of AcaB at 2.9-Å resolution and used this to guide functional analyses that reveal how AcaB binds to DNA. This improved understanding of IncC conjugation provides a basis for the development of new approaches to reduce the spread of these multi-drug-resistance plasmids.
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Affiliation(s)
- Steven J Hancock
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Minh-Duy Phan
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia.
| | - Zhenyao Luo
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Alvin W Lo
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Kate M Peters
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Nguyen Thi Khanh Nhu
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Brian M Forde
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Jason Whitfield
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Ji Yang
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Richard A Strugnell
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - David L Paterson
- The University of Queensland Centre for Clinical Research, Brisbane, Queensland, Australia
| | | | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia.
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.
| | - Scott A Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia.
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11
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McMillan EA, Jackson CR, Frye JG. Transferable Plasmids of Salmonella enterica Associated With Antibiotic Resistance Genes. Front Microbiol 2020; 11:562181. [PMID: 33133037 PMCID: PMC7578388 DOI: 10.3389/fmicb.2020.562181] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/17/2020] [Indexed: 12/11/2022] Open
Abstract
Salmonella enterica is a common foodborne illness in the United States and globally. An increasing number of Salmonella infections are resistant to antibiotics, and many of the genes responsible for those resistances are carried by plasmids. Plasmids are important mediators of horizontal gene exchange, which could potentially increase the spread of antibiotic resistance (AR) genes. Twenty-eight different incompatibility groups of plasmids have been described in Enterobacteriaceae. Incompatibility groups differ in their accessory gene content, replication mechanisms, and their associations with Salmonella serotypes and animal sources. Plasmids also differ in their ability to conjugate or be mobilized, essential genes, and conditions required for transfer. It is important to understand the differences in gene content and transfer mechanisms to accurately determine the impact of plasmids on the dissemination and persistence of antibiotic resistance genes. This review will cover the most common plasmid incompatibility groups present in S. enterica with a focus on the transfer mechanisms and associated antibiotic resistance genes.
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Affiliation(s)
- Elizabeth A McMillan
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, GA, United States
| | - Charlene R Jackson
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, GA, United States
| | - Jonathan G Frye
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, GA, United States
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12
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Antibiotic Resistance in Vibrio cholerae: Mechanistic Insights from IncC Plasmid-Mediated Dissemination of a Novel Family of Genomic Islands Inserted at trmE. mSphere 2020; 5:5/4/e00748-20. [PMID: 32848007 PMCID: PMC7449626 DOI: 10.1128/msphere.00748-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The increasing association of the etiological agent of cholera, Vibrio cholerae serogroup O1 and O139, with multiple antibiotic resistance threatens to deprive health practitioners of this effective tool. Drug resistance in cholera results mainly from acquisition of mobile genetic elements. Genomic islands conferring multidrug resistance and mobilizable by IncC conjugative plasmids were reported to circulate in non-O1/non-O139 V. cholerae clinical strains isolated from the 2010 Haitian cholera outbreak. As these genomic islands can be transmitted to pandemic V. cholerae serogroups, their mechanism of transmission needed to be investigated. Our research revealed plasmid- and genomic island-encoded factors required for the resistance island excision, mobilization, and integration, as well as regulation of these functions. The discovery of related genomic islands carrying diverse phage resistance genes but lacking antibiotic resistance-conferring genes in a wide range of marine dwelling bacteria suggests that these elements are ancient and recently acquired drug resistance genes. Cholera remains a formidable disease, and reports of multidrug-resistant strains of the causative agent Vibrio cholerae have become common during the last 3 decades. The pervasiveness of resistance determinants has largely been ascribed to mobile genetic elements, including SXT/R391 integrative conjugative elements, IncC plasmids, and genomic islands (GIs). Conjugative transfer of IncC plasmids is activated by the master activator AcaCD whose regulatory network extends to chromosomally integrated GIs. MGIVchHai6 is a multidrug resistance GI integrated at the 3′ end of trmE (mnmE or thdF) in chromosome 1 of non-O1/non-O139 V. cholerae clinical isolates from the 2010 Haitian cholera outbreak. In the presence of an IncC plasmid expressing AcaCD, MGIVchHai6 excises from the chromosome and transfers at high frequency. Herein, the mechanism of mobilization of MGIVchHai6 GIs by IncC plasmids was dissected. Our results show that AcaCD drives expression of GI-borne genes, including xis and mobIM, involved in excision and mobilization. A 49-bp fragment upstream of mobIM was found to serve as the minimal origin of transfer (oriT) of MGIVchHai6. The direction of transfer initiated at oriT was determined using IncC plasmid-driven mobilization of chromosomal markers via MGIVchHai6. In addition, IncC plasmid-encoded factors, including the relaxase TraI, were found to be required for GI transfer. Finally, in silico exploration of Gammaproteobacteria genomes identified 47 novel related and potentially AcaCD-responsive GIs in 13 different genera. Despite sharing conserved features, these GIs integrate at trmE, yicC, or dusA and carry a diverse cargo of genes involved in phage resistance. IMPORTANCE The increasing association of the etiological agent of cholera, Vibrio cholerae serogroup O1 and O139, with multiple antibiotic resistance threatens to deprive health practitioners of this effective tool. Drug resistance in cholera results mainly from acquisition of mobile genetic elements. Genomic islands conferring multidrug resistance and mobilizable by IncC conjugative plasmids were reported to circulate in non-O1/non-O139 V. cholerae clinical strains isolated from the 2010 Haitian cholera outbreak. As these genomic islands can be transmitted to pandemic V. cholerae serogroups, their mechanism of transmission needed to be investigated. Our research revealed plasmid- and genomic island-encoded factors required for the resistance island excision, mobilization, and integration, as well as regulation of these functions. The discovery of related genomic islands carrying diverse phage resistance genes but lacking antibiotic resistance-conferring genes in a wide range of marine dwelling bacteria suggests that these elements are ancient and recently acquired drug resistance genes.
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Meinersmann RJ. The biology of IncI2 plasmids shown by whole-plasmid multi-locus sequence typing. Plasmid 2019; 106:102444. [PMID: 31629716 DOI: 10.1016/j.plasmid.2019.102444] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/24/2019] [Accepted: 09/24/2019] [Indexed: 10/25/2022]
Abstract
IncI2 type plasmids are medium-sized (~55-80 kb) conjugative plasmids that have been found carrying important antimicrobial resistance genes but have also been frequently found as cryptic plasmids. The DNA sequences for 147 fully sequenced IncI2 plasmids were studied by a whole-plasmid multi-locus sequence typing (wpMLST) scheme. A total of 171 loci were identified of which 52 were considered core (carried by greater than 95% of the plasmids). Most of the plasmids carrying the antimicrobial gene mcr-1 were in a distinct clade while most of the antimicrobial gene free plasmids were more distantly related. However, the host strains of bacteria were disparate for both groups of plasmids, showing that conjugal transfer of IncI2 plasmid is frequent. The mcr-1 gene was likely to have been introduced into IncI2 plasmids multiple times. It was also observed that the genes for conjugation showed significant linkage disequilibrium despite substantial diversity for most of those genes. Genes associated with biofilm formation were also among the core genes. The core genes can be considered the cohesive unit that defines the IncI2 plasmid group. Given the role conjugation can play in biofilm formation, it was concluded that conjugation is an active survival strategy for IncI2 plasmids. The IncI2 plasmid will have selective advantage when the plasmid-bearing bacteria are introduced to a new animal host that carries potential conjugal mates.
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Affiliation(s)
- Richard J Meinersmann
- U.S. National Poultry Research Center, USDA Agricultural Research Service, 950 College Station Road, Athens, GA 30605, USA.
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14
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Kiss J, Szabó M, Hegyi A, Douard G, Praud K, Nagy I, Olasz F, Cloeckaert A, Doublet B. Identification and Characterization of oriT and Two Mobilization Genes Required for Conjugative Transfer of Salmonella Genomic Island 1. Front Microbiol 2019; 10:457. [PMID: 30894848 PMCID: PMC6414798 DOI: 10.3389/fmicb.2019.00457] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/20/2019] [Indexed: 11/13/2022] Open
Abstract
The integrative mobilizable elements of SGI1-family considerably contribute to the spread of resistance to critically important antibiotics among enteric bacteria. Even though many aspects of SGI1 mobilization by IncA and IncC plasmids have been explored, the basic transfer elements such as oriT and self-encoded mobilization proteins remain undiscovered. Here we describe the mobilization region of SGI1 that is well conserved throughout the family and carries the oriT SGI1 and two genes, mpsA and mpsB (originally annotated as S020 and S019, respectively) that are essential for the conjugative transfer of SGI1. OriT SGI1, which is located in the vicinity of the two mobilization genes proved to be a 125-bp GC-rich sequence with several important inverted repeat motifs. The mobilization proteins MpsA and MpsB are expressed from a bicistronic mRNA, although MpsB can be produced from its own mRNA as well. The protein structure predictions imply that MpsA belongs to the lambda tyrosine recombinase family, while MpsB resembles the N-terminal core DNA binding domains of these enzymes. The results suggest that MpsA may act as an atypical relaxase, which needs MpsB for SGI1 transfer. Although the helper plasmid-encoded relaxase proved not to be essential for SGI1 transfer, it appeared to be important to achieve the high transfer rate of the island observed with the IncA/IncC-SGI1 system.
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Affiliation(s)
- János Kiss
- National Agricultural Research and Innovation Centre, Agricultural Biotechnology Institute, Gödöllõ, Hungary
| | - Mónika Szabó
- National Agricultural Research and Innovation Centre, Agricultural Biotechnology Institute, Gödöllõ, Hungary
| | - Anna Hegyi
- National Agricultural Research and Innovation Centre, Agricultural Biotechnology Institute, Gödöllõ, Hungary.,ISP, Institut National de la Recherche Agronomique, Université de Tours, UMR 1282, Nouzilly, France
| | - Gregory Douard
- ISP, Institut National de la Recherche Agronomique, Université de Tours, UMR 1282, Nouzilly, France
| | - Karine Praud
- ISP, Institut National de la Recherche Agronomique, Université de Tours, UMR 1282, Nouzilly, France
| | - István Nagy
- National Agricultural Research and Innovation Centre, Agricultural Biotechnology Institute, Gödöllõ, Hungary
| | - Ferenc Olasz
- National Agricultural Research and Innovation Centre, Agricultural Biotechnology Institute, Gödöllõ, Hungary
| | - Axel Cloeckaert
- ISP, Institut National de la Recherche Agronomique, Université de Tours, UMR 1282, Nouzilly, France
| | - Benoît Doublet
- ISP, Institut National de la Recherche Agronomique, Université de Tours, UMR 1282, Nouzilly, France
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Ambrose SJ, Harmer CJ, Hall RM. Evolution and typing of IncC plasmids contributing to antibiotic resistance in Gram-negative bacteria. Plasmid 2018; 99:40-55. [PMID: 30081066 DOI: 10.1016/j.plasmid.2018.08.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/12/2018] [Accepted: 08/02/2018] [Indexed: 01/14/2023]
Abstract
The large, broad host range IncC plasmids are important contributors to the spread of key antibiotic resistance genes and over 200 complete sequences of IncC plasmids have been reported. To track the spread of these plasmids accurate typing to identify the closest relatives is needed. However, typing can be complicated by the high variability in resistance gene content and various typing methods that rely on features of the conserved backbone have been developed. Plasmids can be broadly typed into two groups, type 1 and type 2, using four features that differentiate the otherwise closely related backbones. These types are found in many different countries in bacteria from humans and animals. However, hybrids of type 1 and type 2 are also occasionally seen, and two further types, each represented by a single plasmid, were distinguished. Generally, the antibiotic resistance genes are located within a small number of resistance islands, only one of which, ARI-B, is found in both type 1 and type 2. The introduction of each resistance island generates a new lineage and, though they are continuously evolving via the loss of resistance genes or introduction of new ones, the island positions serve as valuable lineage-specific markers. A current type 2 lineage of plasmids is derived from an early type 2 plasmid but the sequences of early type 1 plasmids include features not seen in more recent type 1 plasmids, indicating a shared ancestor rather than a direct lineal relationship. Some features, including ones essential for maintenance or for conjugation, have been examined experimentally.
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Affiliation(s)
- Stephanie J Ambrose
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Christopher J Harmer
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia.
| | - Ruth M Hall
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
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Lorenzo-Díaz F, Fernández-López C, Guillén-Guío B, Bravo A, Espinosa M. Relaxase MobM Induces a Molecular Switch at Its Cognate Origin of Transfer. Front Mol Biosci 2018; 5:17. [PMID: 29600250 PMCID: PMC5863519 DOI: 10.3389/fmolb.2018.00017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/09/2018] [Indexed: 11/13/2022] Open
Abstract
The MOBV1 family of relaxases is broadly distributed in plasmids and other mobile genetic elements isolated from staphylococci, enterococci, and streptococci. The prototype of this family is protein MobM encoded by the streptococcal promiscuous plasmid pMV158. MobM cleaves the phosphodiester bond of a specific dinucleotide within the origin of transfer (oriT) to initiate conjugative transfer. Differently from other relaxases, MobM and probably other members of the family, cleaves its target single-stranded DNA through a histidine residue rather than the commonly used tyrosine. The oriT of the MOBV1 family differs from other well-known conjugative systems since it has sequences with three inverted repeats, which were predicted to generate three mutually-exclusive hairpins on supercoiled DNA. In this work, such hypothesis was evaluated through footprinting experiments on supercoiled plasmid DNA. We have found a change in hairpin extrusion mediated by protein MobM. This conformational change involves a shift from the main hairpin generated on “naked” DNA to a different hairpin in which the nick site is positioned in a single-stranded configuration. Our results indicate that the oriTpMV158 acts as a molecular switch in which, depending on the inverted repeat recognized by MobM, pMV158 mobilization could be turned “on” or “off.”
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Affiliation(s)
- Fabián Lorenzo-Díaz
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.,Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | | | - Beatriz Guillén-Guío
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.,Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Alicia Bravo
- Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
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