id: Pfam:PF09957
pfam_id: PF09957
name: Bacterial antitoxin of type II TA system, VapB
short_name: VapB_antitoxin
seed_status: EX_DUF
characterization_status: UNSCORED
curation_status: SEEDED
source_url: https://www.ebi.ac.uk/interpro/api/entry/pfam/PF09957
counters:
  proteins: 3852
  matches: 3852
  proteomes: 2644
  taxa: 4342
  structures: 2
  alphafold_models: 2335
  domain_architectures: 9
provenance:
  snapshot_id: interpro-pfam-duf-2026-10-10
  path: data/worklists/interpro-pfam-duf-2026-10-10.json
  sha256: 17fb625876c9326ed284263a47bcd84e0d7844a31c040dc06cd2260c36f1c383
  generated_at: '2026-10-10T07:44:21.614711Z'
  source_url: https://www.ebi.ac.uk/interpro/api/entry/pfam/
interpro_id: InterPro:IPR019239
description: VapB is the antitoxin of a bacterial toxin-antitoxin gene pair. The cognate toxin is VapC,
  [pfam:PF05016]. The family contains several related antitoxins from Cyanobacteria and Actinobacterial
  families. Antitoxins of this class carry an N-terminal ribbon-helix-helix domain, RHH, that is highly
  conserved across all type II bacterial antitoxins, which dimerises with the RHH domain of a second VapB
  molecule. A hinge section follows the RHH, with an additional pair of flexible alpha helices at the
  C-terminus. This C-terminus is the Toxin-binding region of the dimer, and so is specific to the cognate
  toxin, whereas the RHH domain has the specific function of lying across the RNA-binding groove of the
  toxin dimer and inactivating the active-site - a more general function of all antitoxins.