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Chaudhary S, Ali W, Yadav M, Singh G, Gupta N, Grover S, Ghosh C, Chandra S, Rathore JS. Computational exploration of the genomic assignments, molecular structure, and dynamics of the ccdABXn2 toxin-antitoxin homolog with its bacterial target, the DNA gyrase, in the entomopathogen Xenorhabdus nematophila. J Biomol Struct Dyn 2024:1-15. [PMID: 38321949 DOI: 10.1080/07391102.2024.2311337] [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: 11/09/2023] [Accepted: 01/23/2024] [Indexed: 02/08/2024]
Abstract
Toxin-antitoxin (TA) modules, initially discovered on bacterial plasmids and subsequently identified within chromosomal contexts, hold a pivotal role in the realm of bacterial physiology. Among these, the pioneering TA system, ccd (Control of Cell Death), primarily localized on the F-plasmid, is known for its orchestration of plasmid replication with cellular division. Nonetheless, the precise functions of such systems within bacterial chromosomal settings remain a compelling subject that demands deeper investigation. To bridge this knowledge gap, our study focuses on exploring ccdABXn2, a chromosomally encoded TA module originating from the entomopathogenic bacterium Xenorhabdus nematophila. We meticulously delved into the system's genomic assignments, structural attributes, and functional interplay. Our findings uncovered intriguing patterns-CcdB toxin homologs exhibited higher conservation levels compared to their CcdA antitoxin counterparts. Moreover, we constructed secondary as well as tertiary models for both the CcdB toxin and CcdA antitoxin using threading techniques and subsequently validated their structural integrity. Our exploration extended to the identification of key interactions, including the peptide interaction with gyrase for the CcdB homolog and CcdB toxin interactions for the CcdA homolog, highlighting the intricate TA interaction network. Through docking and simulation analyses, we unequivocally demonstrated the inhibition of replication via binding the CcdB toxin to its target, DNA gyrase. These insights provide valuable knowledge about the metabolic and physiological roles of the chromosomally encoded ccdABXn2 TA module within the context of X. nematophila, significantly enhancing our comprehension of its functional significance within the intricate ecosystem of the bacterial host.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Shobhi Chaudhary
- School of Biotechnology, Gautam Buddha University, Greater Noida, India
| | - Waseem Ali
- Department of Molecular Medicine, Jamia Hamdard, New Delhi, India
| | - Mohit Yadav
- School of Biotechnology, Gautam Buddha University, Greater Noida, India
- Department of Molecular Biology and Biotechnology, Tezpur University, Assam, India
| | - Garima Singh
- School of Biotechnology, Gautam Buddha University, Greater Noida, India
| | - Nomita Gupta
- School of Biotechnology, Gautam Buddha University, Greater Noida, India
| | - Sonam Grover
- Department of Molecular Medicine, Jamia Hamdard, New Delhi, India
| | - Chaitali Ghosh
- Department of Zoology, Gargi College, University of Delhi, New Delhi, India
| | - Subhash Chandra
- Computational Biology & Biotechnology Laboratory, Department of Botany, Soban Singh Jeena University, Almora, India
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Wang X, Kan Y, Bai K, Xu X, Chen X, Yu C, Shi J, Jiang N, Li J, Luo L. A novel double-ribonuclease toxin-antitoxin system linked to the stress response and survival of Acidovorax citrulli. Microbiol Spectr 2023; 11:e0216923. [PMID: 37819152 PMCID: PMC10714953 DOI: 10.1128/spectrum.02169-23] [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: 05/25/2023] [Accepted: 08/30/2023] [Indexed: 10/13/2023] Open
Abstract
IMPORTANCE Bacterial fruit blotch (BFB), which is caused by the seed-borne bacterium Acidovorax citrulli, is a devastating disease affecting cucurbit crops throughout the world. Although seed fermentation and treatment with disinfectants can provide effective management of BFB, they cannot completely guarantee pathogen-free seedstock, which suggests that A. citrulli is a highly stress-resistant pathogen. Toxin-antitoxin (TA) systems are common among a diverse range of bacteria and have been reported to play a role in bacterial stress response. However, there is currently much debate about the relationship between TA systems and stress response in bacteria. The current study characterized a novel TA system (Aave_1720-Aave_1719) from A. citrulli that affects both biofilm formation and survival in response to sodium hypochlorite stress. The mechanism of neutralization differed from typical TA systems as two separate mechanisms were associated with the antitoxin, which exhibited characteristics of both type II and type V TA systems. The Aave_1720-Aave_1719 system described here also constitutes the first known report of a double-ribonuclease TA system in bacteria, which expands our understanding of the range of regulatory mechanisms utilized by bacterial TA systems, providing new insight into the survival of A. citrulli in response to stress.
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Affiliation(s)
- Xudong Wang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Yumin Kan
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, New York, USA
| | - Kaihong Bai
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Xiaoli Xu
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Xing Chen
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Chengxuan Yu
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Jia Shi
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Na Jiang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Jianqiang Li
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Laixin Luo
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
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Chaudhary S, Yadav M, Mathpal S, Chandra S, Rathore JS. Genomic assortment and interactive insights of the chromosomal encoded control of cell death ( ccd) toxin-antitoxin (TA) module in Xenorhabdus nematophila. J Biomol Struct Dyn 2023; 41:7032-7044. [PMID: 36002267 DOI: 10.1080/07391102.2022.2114940] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 08/14/2022] [Indexed: 10/15/2022]
Abstract
In the present circumstances, toxin-antitoxin (TA) modules have a great consideration due to their elusive role in bacterial physiology. TA modules consist of a toxic part and a counteracting antitoxin part and these are abundant genetic loci harbored on bacterial plasmids and chromosomes. The control of cell death (ccd) TA locus was the first identified TA module and its unitary function (such as plasmid maintenance) has been described, however, the function of its chromosomal counterparts is still ambiguous. Here, we are exploring the genomic assortment, structural and functional association of chromosomally encoded ccdAB TA homolog (ccdABXn1) in the genome of an entomopathogenic bacterium Xenorhabdus nematophila. This bacterium is a symbiotic model with the nematode Steinernema carpocapsae that infects and kills the host insect. By genomic assortment analysis, our observations suggested that CcdA antitoxin homologs are not more closely related than CcdB toxin homologs. Further results suggest that the ccdABXn1 TA homolog has sulphonamide (such as 4C6, for CcdA homolog) and peptide (such as gyrase, for CcdB homolog) ligand partners with a typical TA interaction network that may affect essential cellular metabolism of the X. nematophila. Collectively, our results improve the knowledge and conception of the metabolic interactive role of ccdAB TA homologs in X. nematophila physiology.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Shobhi Chaudhary
- Gautam Buddha University, School of Biotechnology, Greater Noida, Uttar Pradesh, India
| | - Mohit Yadav
- Gautam Buddha University, School of Biotechnology, Greater Noida, Uttar Pradesh, India
| | - Shalini Mathpal
- Department of Biotechnology, Kumaun University Uttarakhand, Bhimtal, India
| | - Subhash Chandra
- Department of Botany, Computational Biology & Biotechnology Laboratory, Soban Singh Jeena University, Almora, Uttarakhand, India
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Krin E, Baharoglu Z, Sismeiro O, Varet H, Coppée JY, Mazel D. Systematic transcriptome analysis allows the identification of new type I and type II Toxin/Antitoxin systems located in the superintegron of Vibrio cholerae. Res Microbiol 2023; 174:103997. [PMID: 36347445 DOI: 10.1016/j.resmic.2022.103997] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 11/07/2022]
Abstract
Vibrio cholerae N16961 genome encodes 18 type II Toxin/Antitoxin (TA) systems, all but one located inside gene cassettes of its chromosomal superintegron (SI). This study aims to investigate additional TA systems in this genome. We screened for all two-genes operons of uncharacterized function by analyzing previous RNAseq data. Assays on nine candidates, revealed one additional functional type II TA encoded by the VCA0497-0498 operon, carried inside a SI cassette. We showed that VCA0498 antitoxin alone and in complex with VCA0497 represses its own operon promoter. VCA0497-0498 is the second element of the recently identified dhiT/dhiA superfamily uncharacterized type II TA system. RNAseq analysis revealed that another SI cassette encodes a novel type I TA system: VCA0495 gene and its two associated antisense non-coding RNAs, ncRNA495 and ncRNA496. Silencing of both antisense ncRNAs lead to cell death, demonstrating the type I TA function. Both VCA0497 and VCA0495 toxins do not show any homology to functionally characterized toxins, however our preliminary data suggest that their activity may end up in mRNA degradation, directly or indirectly. Our findings increase the TA systems number carried in this SI to 19, preferentially located in its distal end, confirming their importance in this large cassette array.
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Affiliation(s)
- Evelyne Krin
- Institut Pasteur, Université Paris Cité, CNRS UMR 3525, Unité de Plasticité du Génome Bactérien, 28 rue du Docteur Roux, F-75015 Paris, France.
| | - Zeynep Baharoglu
- Institut Pasteur, Université Paris Cité, CNRS UMR 3525, Unité de Plasticité du Génome Bactérien, 28 rue du Docteur Roux, F-75015 Paris, France.
| | - Odile Sismeiro
- Institut Pasteur, Université Paris Cité, Transcriptome and EpiGenome, Biomics Center for Innovation and Technological Research, 28 rue du Docteur Roux, F-75015 Paris, France.
| | - Hugo Varet
- Institut Pasteur, Université Paris Cité, Transcriptome and EpiGenome, Biomics Center for Innovation and Technological Research, 28 rue du Docteur Roux, F-75015 Paris, France.
| | - Jean-Yves Coppée
- Institut Pasteur, Université Paris Cité, Transcriptome and EpiGenome, Biomics Center for Innovation and Technological Research, 28 rue du Docteur Roux, F-75015 Paris, France.
| | - Didier Mazel
- Institut Pasteur, Université Paris Cité, CNRS UMR 3525, Unité de Plasticité du Génome Bactérien, 28 rue du Docteur Roux, F-75015 Paris, France.
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