id: Pfam:PF09369
pfam_id: PF09369
name: MrfA Zn-binding domain
short_name: MZB
seed_status: EX_DUF
characterization_status: UNSCORED
curation_status: SEEDED
source_url: https://www.ebi.ac.uk/interpro/api/entry/pfam/PF09369
counters:
  proteins: 11160
  matches: 11161
  proteomes: 8342
  taxa: 13990
  structures: 5
  alphafold_models: 5747
  domain_architectures: 99
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:IPR018973
description: This is the C-terminal MrfA Zn+2-binding domain (MZB, also referred to as DUF1998) which
  contains a conserved four-cysteine signature motif. These four Cys reside in a short coil between two
  alpha-helices and form a metal ion-binding site [[cite:PUB00098193]]. This domain is frequently found
  at the C-terminal of ndNTPases, however, it is also found encoded in a standalone gene, downstream of
  putative helicase domain-encoding genes associated with bacterial anti-phage defense system DISARM.
  MrfA (Mitomycin repair factor A, also known as YprA in Bacillus subtilis) is a DNA helicase that supports
  repair of mitomycin C-induced DNA damage. MrfA homologues are widely distributed in bacteria and are
  also present in archaea, fungi and plants. The MrfA-homologue in yeast, Hrq1, also reduces mitomycin
  C sensitivity. Hrq1 has high similarity to human RecQ4 and was therefore assigned to the RecQ-like helicase
  family. MrfA homologues appear to be missing in Enterobacteria, however, certain pathogenic Escherichia
  coli and Salmonella strains harbour Z5898-like helicases with this domain [[cite:PUB00098193]].