Evidence map›Paper›PMID 42306950›Full record

ArticleNucleic acids research2026

Structural and functional characterization of VapBC52 toxin-antitoxin system from Mycobacterium tuberculosis.

Manisha Singh, Charandeep Singh, Akshay V Nair, Imran Ahmad, Arun Sharma, Munmun Bhasin, Vikas Jain, Ramandeep Singh, Krishan Gopal Thakur

Abstract read
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Article in Nucleic acids research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

9 authors.

Manisha SinghCentre for Tuberculosis Research, Tuberculosis Research Laboratory, BRIC-Translational Health Science and Technology Institute, Faridabad-Gurugram Expressway, Faridabad, Haryana 121001, India.
Charandeep SinghStructural Biology Laboratory, CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India.
Akshay V NairMicrobiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Madhya Pradesh 462066, India.
Imran AhmadCentre for Tuberculosis Research, Tuberculosis Research Laboratory, BRIC-Translational Health Science and Technology Institute, Faridabad-Gurugram Expressway, Faridabad, Haryana 121001, India.
Arun SharmaCentre for Tuberculosis Research, Tuberculosis Research Laboratory, BRIC-Translational Health Science and Technology Institute, Faridabad-Gurugram Expressway, Faridabad, Haryana 121001, India.
Munmun BhasinMolecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
Vikas JainLaboratory of Antimicrobial Innovation, School of Interwoven Arts and Sciences, Krea University, Sri City, Andhra Pradesh 517646, India.ORCID 0000-0003-0238-8144
Ramandeep SinghCentre for Tuberculosis Research, Tuberculosis Research Laboratory, BRIC-Translational Health Science and Technology Institute, Faridabad-Gurugram Expressway, Faridabad, Haryana 121001, India.ORCID 0000-0003-2705-3826
Krishan Gopal ThakurStructural Biology Laboratory, CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India.ORCID 0000-0003-4500-2133

Funding

Anusandhan National Research Foundation SPR/2023/000 423Centre of Excellence for Anti-Viral and Anti-Bacterial Drug Discovery and DevelopmentCouncil of Scientific and Industrial Research OLP0162DBT-Wellcome Trust India IA/S/19/2/504 646Department of Pharmaceuticals, Government of India, New Delhi
6 · The paper itself

Abstract

Mycobacterium tuberculosis (Mtb) encodes a huge repertoire of toxin-antitoxin (TA) systems, many of which remain uncharacterized. Here, we report the crystal structures of the VapC52 toxin and VapBC52 TA complex at a resolution of 2.6 and 3.2 Å, respectively. We show that VapC52 adopts a unique open dimeric conformation and inhibits mycobacterial growth by cleaving tRNA at the variable or anticodon loop region. Structure reveals that VapB52 adopts a distinct structural architecture and binds VapC52 with a 1:2 stoichiometry, respectively. Interestingly, binding of ssDNA activates VapB52 peptidase domain, resulting in auto-cleavage of VapB52 N-terminal domain which is critical for VapBC complex formation and neutralization. In addition to VapB52, co-expression of several other non-cognate VapB antitoxins abrogates the growth inhibition associated with VapC52 overexpression in Mycobacterium smegmatis (Msm) suggesting crosstalk among VapBC TA systems. Further, we demonstrate that the vapBC52 locus is dispensable for in vitro growth but essential for Mtb intracellular growth in macrophages and guinea pigs. Notably, VapC52 also cleaves mycobacteriophage D29 encoded tRNAs and confers resistance to phage infection in Msm. Taken together, we show that VapBC52 adopts a unique structural architecture, plays role in pathogenesis, and is possibly involved in mycobacterial antiphage defense mechanisms.

Indexed as

Bacterial ProteinsBacterial ToxinsMycobacterium tuberculosisToxin-Antitoxin SystemsAnimalsCrystallography, X-RayDNA-Binding ProteinsDNA, Single-StrandedGuinea PigsMacrophagesMembrane GlycoproteinsModels, MolecularMycobacterium smegmatisRNA, TransferBacterial ProteinsBacterial ToxinsDNA-Binding ProteinsDNA, Single-StrandedMembrane GlycoproteinsRNA, TransferVapB protein, Bacteria

Identifiers

PMID42306950
PMCPMC13273310

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.