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Kishida K, Li YG, Ogawa-Kishida N, Khara P, Al Mamun AAM, Bosserman RE, Christie PJ. Chimeric systems composed of swapped Tra subunits between distantly-related F plasmids reveal striking plasticity among type IV secretion machines. PLoS Genet 2024; 20:e1011088. [PMID: 38437248 PMCID: PMC10939261 DOI: 10.1371/journal.pgen.1011088] [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: 12/02/2023] [Revised: 03/14/2024] [Accepted: 02/20/2024] [Indexed: 03/06/2024] Open
Abstract
Bacterial type IV secretion systems (T4SSs) are a versatile family of macromolecular translocators, collectively able to recruit diverse DNA and protein substrates and deliver them to a wide range of cell types. Presently, there is little understanding of how T4SSs recognize substrate repertoires and form productive contacts with specific target cells. Although T4SSs are composed of a number of conserved subunits and adopt certain conserved structural features, they also display considerable compositional and structural diversity. Here, we explored the structural bases underlying the functional versatility of T4SSs through systematic deletion and subunit swapping between two conjugation systems encoded by the distantly-related IncF plasmids, pED208 and F. We identified several regions of intrinsic flexibility among the encoded T4SSs, as evidenced by partial or complete functionality of chimeric machines. Swapping of VirD4-like TraD type IV coupling proteins (T4CPs) yielded functional chimeras, indicative of relaxed specificity at the substrate-TraD and TraD-T4SS interfaces. Through mutational analyses, we further delineated domains of the TraD T4CPs contributing to recruitment of cognate vs heterologous DNA substrates. Remarkably, swaps of components comprising the outer membrane core complexes, a few F-specific subunits, or the TraA pilins supported DNA transfer in the absence of detectable pilus production. Among sequenced enterobacterial species in the NCBI database, we identified many strains that harbor two or more F-like plasmids and many F plasmids lacking one or more T4SS components required for self-transfer. We confirmed that host cells carrying co-resident, non-selftransmissible variants of pED208 and F elaborate chimeric T4SSs, as evidenced by transmission of both plasmids. We propose that T4SS plasticity enables the facile assembly of functional chimeras, and this intrinsic flexibility at the structural level can account for functional diversification of this superfamily over evolutionary time and, on a more immediate time-scale, to proliferation of transfer-defective MGEs in nature.
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Affiliation(s)
- Kouhei Kishida
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, Texas, United States of America
| | - Yang Grace Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, Texas, United States of America
| | - Natsumi Ogawa-Kishida
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, Texas, United States of America
| | - Pratick Khara
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, Texas, United States of America
| | - Abu Amar M. Al Mamun
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, Texas, United States of America
| | - Rachel E. Bosserman
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, Texas, United States of America
| | - Peter J. Christie
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, Texas, United States of America
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Giengkam S, Kullapanich C, Wongsantichon J, Adcox HE, Gillespie JJ, Salje J. Orientia tsutsugamushi: comprehensive analysis of the mobilome of a highly fragmented and repetitive genome reveals the capacity for ongoing lateral gene transfer in an obligate intracellular bacterium. mSphere 2023; 8:e0026823. [PMID: 37850800 PMCID: PMC10732058 DOI: 10.1128/msphere.00268-23] [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: 05/15/2023] [Accepted: 08/22/2023] [Indexed: 10/19/2023] Open
Abstract
IMPORTANCE Obligate intracellular bacteria, or those only capable of growth inside other living cells, have limited opportunities for horizontal gene transfer with other microbes due to their isolated replicative niche. The human pathogen Ot, an obligate intracellular bacterium causing scrub typhus, encodes an unusually high copy number of a ~40 gene mobile genetic element that typically facilitates genetic transfer across microbes. This proliferated element is heavily degraded in Ot and previously assumed to be inactive. Here, we conducted a detailed analysis of this element in eight Ot strains and discovered two strains with at least one intact copy. This implies that the element is still capable of moving across Ot populations and suggests that the genome of this bacterium may be even more dynamic than previously appreciated. Our work raises questions about intracellular microbial evolution and sounds an alarm for gene-based efforts focused on diagnosing and combatting scrub typhus.
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Affiliation(s)
- Suparat Giengkam
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chitrasak Kullapanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jantana Wongsantichon
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Haley E. Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, Baltimore, Maryland, USA
| | - Jeanne Salje
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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3
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Kishida K, Li YG, Ogawa-Kishida N, Khara P, Al Mamun AAM, Bosserman RE, Christie PJ. Chimeric systems composed of swapped Tra subunits between distantly-related F plasmids reveal striking plasticity among type IV secretion machines. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.05.570194. [PMID: 38106057 PMCID: PMC10723329 DOI: 10.1101/2023.12.05.570194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Bacterial type IV secretion systems (T4SSs) are a versatile family of macromolecular translocators, collectively able to recruit diverse DNA and protein substrates and deliver them to a wide range of cell types. Presently, there is little understanding of how T4SSs recognize substrate repertoires and form productive contacts with specific target cells. Although T4SSs are composed of a number of conserved subunits and adopt certain conserved structural features, they also display considerable compositional and structural diversity. Here, we explored the structural bases underlying the functional versatility of T4SSs through systematic deletion and subunit swapping between two conjugation systems encoded by the distantly-related IncF plasmids, pED208 and F. We identified several regions of intrinsic flexibility among the encoded T4SSs, as evidenced by partial or complete functionality of chimeric machines. Swapping of VirD4-like TraD type IV coupling proteins (T4CPs) yielded functional chimeras, indicative of relaxed specificity at the substrate - TraD and TraD - T4SS interfaces. Through mutational analyses, we further delineated domains of the TraD T4CPs contributing to recruitment of cognate vs heterologous DNA substrates. Remarkably, swaps of components comprising the outer membrane core complexes, a few F-specific subunits, or the TraA pilins supported DNA transfer in the absence of detectable pilus production. Among sequenced enterobacterial species in the NCBI database, we identified many strains that harbor two or more F-like plasmids and many F plasmids lacking one or more T4SS components required for self-transfer. We confirmed that host cells carrying co-resident, non-selftransmissible variants of pED208 and F elaborate chimeric T4SSs, as evidenced by transmission of both plasmids. We propose that T4SS plasticity enables the facile assembly of functional chimeras, and this intrinsic flexibility at the structural level can account for functional diversification of this superfamily over evolutionary time and, on a more immediate time-scale, to proliferation of transfer-defective MGEs in nature.
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Affiliation(s)
- Kouhei Kishida
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, 6431 Fannin St, Houston, Texas 77030, United States of America
| | - Yang Grace Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, 6431 Fannin St, Houston, Texas 77030, United States of America
| | - Natsumi Ogawa-Kishida
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, 6431 Fannin St, Houston, Texas 77030, United States of America
| | - Pratick Khara
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, 6431 Fannin St, Houston, Texas 77030, United States of America
| | - Abu Amar M Al Mamun
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, 6431 Fannin St, Houston, Texas 77030, United States of America
| | - Rachel E. Bosserman
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, 6431 Fannin St, Houston, Texas 77030, United States of America
| | - Peter J. Christie
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, 6431 Fannin St, Houston, Texas 77030, United States of America
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Bragagnolo N, Audette GF. Solution characterization of the dynamic conjugative entry exclusion protein TraG. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2022; 9:064702. [PMID: 36590369 PMCID: PMC9797247 DOI: 10.1063/4.0000171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
The R100 plasmid and the secretion system it encodes are representative of F-like conjugative type IV secretion systems for the transmission of mobile DNA elements in gram-negative bacteria, serving as a major contributor to the spread of antibiotic resistance in bacterial pathogens. The TraG protein of F-like systems consists of a membrane-bound N-terminal domain and a periplasmic C-terminal domain, denoted TraG*. TraG* is essential in preventing redundant DNA transfer through a process termed entry exclusion. In the donor cell, it interacts with TraN to facilitate mating pair stabilization; however, if a mating pore forms between bacteria with identical plasmids, TraG* interacts with its cognate TraS in the inner membrane of the recipient bacterium to prevent redundant donor-donor conjugation. Structural studies of TraG* from the R100 plasmid have revealed the presence of a dynamic region between the N- and C-terminal domains of TraG. Thermofluor, circular dichroism, collision-induced unfolding-mass spectrometry, and size exclusion chromatography linked to multiangle light scattering and small angle x-ray scattering experiments indicated an N-terminal truncation mutant displayed higher stability and less disordered content relative to full-length TraG*. The 45 N-terminal residues of TraG* are hypothesized to serve as part of a flexible linker between the two independently functioning domains.
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Kishida K, Bosserman RE, Harb L, Khara P, Song L, Hu B, Zeng L, Christie PJ. Contributions of F‐specific Subunits to the F
Plasmid‐Encoded
Type
IV
Secretion System and F pilus. Mol Microbiol 2022; 117:1275-1290. [DOI: 10.1111/mmi.14908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/26/2022] [Accepted: 04/12/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Kouhei Kishida
- Department of Microbiology and Molecular Genetics McGovern Medical School 6431 Fannin St, Houston, Texas 77030
| | - Rachel E. Bosserman
- Department of Microbiology and Molecular Genetics McGovern Medical School 6431 Fannin St, Houston, Texas 77030
- Current address: Department of Medicine, Division of Infectious Diseases Washington School of Medicine St. Louis, MO, 63110
| | - Laith Harb
- Department of Biochemistry and Biophysics, Texas A&M University College Station TX, 77843 USA
- Center for Phage Technology, Texas A&M University College Station TX, 77843 USA
| | - Pratick Khara
- Department of Microbiology and Molecular Genetics McGovern Medical School 6431 Fannin St, Houston, Texas 77030
| | - Liqiang Song
- Department of Microbiology and Molecular Genetics McGovern Medical School 6431 Fannin St, Houston, Texas 77030
| | - Bo Hu
- Department of Microbiology and Molecular Genetics McGovern Medical School 6431 Fannin St, Houston, Texas 77030
| | - Lanying Zeng
- Department of Biochemistry and Biophysics, Texas A&M University College Station TX, 77843 USA
- Center for Phage Technology, Texas A&M University College Station TX, 77843 USA
| | - Peter J. Christie
- Department of Microbiology and Molecular Genetics McGovern Medical School 6431 Fannin St, Houston, Texas 77030
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Guo W, Huang C, Xi B, Tang Z, Tan W, Li W, Zhang Y, Li W. The maturity period is the main stage of antibiotic resistance genes reduction in aerobic composting process of swine manure in sub-scale farms. BIORESOURCE TECHNOLOGY 2021; 319:124139. [PMID: 32971337 DOI: 10.1016/j.biortech.2020.124139] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/12/2020] [Accepted: 09/13/2020] [Indexed: 06/11/2023]
Abstract
This study was focused on the changes of antibiotic resistance genes (ARGs) and their potential host bacteria during the swine manure composting on sub-scale farms. Eight target ARGs increased 427% on average, with a trend of increase at early stage and decrease at later stage, and the main reduction stage appeared in maturity stage. The abundance of ARGs was mainly affected by the community succession of potential host bacteria. Composting could reduce the abundance of potential host bacteria of ARGs as well as pathogens such as Pseudomonas, and reduce the environmental risks of swine manure. N/C and S levels had a positive effect on the potential host of most ARGs. Prolonging the maturity period would inhibit the growth of potential host bacteria of ARGs during composting, therefore inhibiting the transmission of ARGs.
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Affiliation(s)
- Wei Guo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Caihong Huang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Beidou Xi
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Zhurui Tang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wenbing Tan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Wenxuan Li
- Department of Civil & Environmental Engineering, National University of Singapore, Singapore 117576, Republic of Singapore
| | - Ying Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Wei Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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7
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Virolle C, Goldlust K, Djermoun S, Bigot S, Lesterlin C. Plasmid Transfer by Conjugation in Gram-Negative Bacteria: From the Cellular to the Community Level. Genes (Basel) 2020; 11:genes11111239. [PMID: 33105635 PMCID: PMC7690428 DOI: 10.3390/genes11111239] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/15/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023] Open
Abstract
Bacterial conjugation, also referred to as bacterial sex, is a major horizontal gene transfer mechanism through which DNA is transferred from a donor to a recipient bacterium by direct contact. Conjugation is universally conserved among bacteria and occurs in a wide range of environments (soil, plant surfaces, water, sewage, biofilms, and host-associated bacterial communities). Within these habitats, conjugation drives the rapid evolution and adaptation of bacterial strains by mediating the propagation of various metabolic properties, including symbiotic lifestyle, virulence, biofilm formation, resistance to heavy metals, and, most importantly, resistance to antibiotics. These properties make conjugation a fundamentally important process, and it is thus the focus of extensive study. Here, we review the key steps of plasmid transfer by conjugation in Gram-negative bacteria, by following the life cycle of the F factor during its transfer from the donor to the recipient cell. We also discuss our current knowledge of the extent and impact of conjugation within an environmentally and clinically relevant bacterial habitat, bacterial biofilms.
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8
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Protein Dynamics in F-like Bacterial Conjugation. Biomedicines 2020; 8:biomedicines8090362. [PMID: 32961700 PMCID: PMC7555446 DOI: 10.3390/biomedicines8090362] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 01/21/2023] Open
Abstract
Efficient in silico development of novel antibiotics requires high-resolution, dynamic models of drug targets. As conjugation is considered the prominent contributor to the spread of antibiotic resistance genes, targeted drug design to disrupt vital components of conjugative systems has been proposed to lessen the proliferation of bacterial antibiotic resistance. Advancements in structural imaging techniques of large macromolecular complexes has accelerated the discovery of novel protein-protein interactions in bacterial type IV secretion systems (T4SS). The known structural information regarding the F-like T4SS components and complexes has been summarized in the following review, revealing a complex network of protein-protein interactions involving domains with varying degrees of disorder. Structural predictions were performed to provide insight on the dynamicity of proteins within the F plasmid conjugative system that lack structural information.
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9
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Yang K, Chen QL, Chen ML, Li HZ, Liao H, Pu Q, Zhu YG, Cui L. Temporal Dynamics of Antibiotic Resistome in the Plastisphere during Microbial Colonization. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11322-11332. [PMID: 32812755 DOI: 10.1021/acs.est.0c04292] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The increasing and simultaneous pollution of plastic debris and antibiotic resistance in aquatic environments makes plastisphere a great health concern. However, the development process of antibiotic resistome in the plastisphere is largely unknown, impeding risk assessment associated with plastics. Here, we profiled the temporal dynamics of antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and microbial composition in the plastisphere from initial microbial colonization to biofilm formation in urban water. A total of 82 ARGs, 12 MGEs, and 63 bacterial pathogens were detected in the plastisphere and categorized as the pioneering, intermediate, and persistent ones. The high number of five MGEs and six ARGs persistently detected in the whole microbial colonization process was regarded as a major concern because of their potential role in disseminating antibiotic resistance. In addition to genomic analysis, D2O-labeled single-cell Raman spectroscopy was employed to interrogate the ecophysiology of plastisphere in a culture-independent way and demonstrated that the plastisphere was inherently more tolerant to antibiotics than bacterioplankton. Finally, by combining persistent MGEs, intensified colonization of pathogenic bacteria, increased tolerance to antibiotic, and potential trophic transfer into a holistic risk analysis, the plastisphere was indicated to constitute a hot spot to acquire and spread antibiotic resistance and impose a long-term risk to ecosystems and human health. These findings provide important insights into the antibiotic resistome and ecological risk of the plastisphere and highlight the necessity for comprehensive surveillance of plastisphere.
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Affiliation(s)
- Kai Yang
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Qing-Lin Chen
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Mo-Lian Chen
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Hong-Zhe Li
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Hu Liao
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Qiang Pu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Yong-Guan Zhu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Li Cui
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
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10
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Koch B, Callaghan MM, Tellechea-Luzardo J, Seeger AY, Dillard JP, Krasnogor N. Protein interactions within and between two F-type type IV secretion systems. Mol Microbiol 2020; 114:823-838. [PMID: 32738086 DOI: 10.1111/mmi.14582] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 01/03/2023]
Abstract
Bacterial type IV secretion systems (T4SSs) can mediate conjugation. The T4SS from Neisseria gonorrhoeae possesses the unique ability to mediate DNA secretion into the extracellular environment. The N. gonorrhoeae T4SS can be grouped with F-type conjugative T4SSs based on homology. We tested 17 proteins important for DNA secretion by N. gonorrhoeae for protein interactions. The BACTH-TM bacterial two-hybrid system was successfully used to study periplasmic interactions. By determining if the same interactions were observed for F-plasmid T4SS proteins and when one interaction partner was replaced by the corresponding protein from the other T4SS, we aimed to identify features associated with the unique function of the N. gonorrhoeae T4SS as well as generic features of F-type T4SSs. For both systems, we observed already described interactions shared by homologs from other T4SSs as well as new and described interactions between F-type T4SS-specific proteins. Furthermore, we demonstrate, for the first-time, interactions between proteins with homology to the conserved T4SS outer membrane core proteins and F-type-specific proteins and we confirmed two of them by co-purification. The F-type-specific protein TraHN was found to localize to the outer membrane and the presence of significant amounts of TraHN in the outer membrane requires TraGN .
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Affiliation(s)
- Birgit Koch
- Interdisciplinary Computing and Complex BioSystems (ICOS), School of Computing Science, Newcastle University, Newcastle upon Tyne, UK
| | - Melanie M Callaghan
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Jonathan Tellechea-Luzardo
- Interdisciplinary Computing and Complex BioSystems (ICOS), School of Computing Science, Newcastle University, Newcastle upon Tyne, UK
| | - Ami Y Seeger
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Joseph P Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Natalio Krasnogor
- Interdisciplinary Computing and Complex BioSystems (ICOS), School of Computing Science, Newcastle University, Newcastle upon Tyne, UK
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