id: Pfam:PF07254
pfam_id: PF07254
name: Membrane-bound toxin component of toxin-antitoxin system
short_name: Cpta_toxin
seed_status: EX_DUF
characterization_status: UNSCORED
curation_status: SEEDED
source_url: https://www.ebi.ac.uk/interpro/api/entry/pfam/PF07254
counters:
  proteins: 1964
  matches: 1965
  proteomes: 1959
  taxa: 2784
  structures: 0
  alphafold_models: 1173
  domain_architectures: 4
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:IPR009883
description: CptA is a family of bacterial proteins named for the member of this family, YGFX_ECOLI, Swissprot:Q46824.
  YgfX was previously thought to be the toxic part of a toxin-antitoxin module [[cite:PUB00075551]] along
  with the antitoxin, [pfam:PF03937] Sdh5. However, studies have shown that, YgfX interferes with correct
  cell division and morphology. Furthermore, the function of YgfX-SdhE as a TA system could not be demonstrated
  in either E. coli or Serratia sp. ATCC 39006. YgfX is predicted to have a short N-terminal cytoplasmic
  domain followed by two transmembrane helices (TMHs) separated by a short periplasmic loop and finally,
  a larger C-terminal cytoplasmic domain. The TMHs of YgfX are required for activity, but the sequence
  of the cytoplasmic 13 N-terminal amino acids is not essential. Furthermore, the amino acids W34 and
  D117 are not required for localization but are necessary for YgfX multimerization, interaction with
  SdhE, and YgfX activity. It is proposed that the formation of YgfX multimeric membrane-bound proteins
  are required to enable the interaction with the cytoplasmic SDH assembly factor SdhE [[cite:PUB00083888]].
  Another study has demonstrated that sdhEygfX (bicistronic operon) affects pig biosynthesis, directly
  or indirectly, at the level of transcription of the biosynthetic operon (pigA-O) [[cite:PUB00066693]].
  It has also been suggested that, in addition to indirect transcriptional activation of pigA-O, YgfX
  might facilitate the formation of a terminal pig biosynthetic complex consisting of PigB and PigC [[cite:PUB00083888]].