id: Pfam:PF13699
pfam_id: PF13699
name: eCIS core domain
short_name: eCIS_core
seed_status: EX_DUF
characterization_status: UNSCORED
curation_status: SEEDED
source_url: https://www.ebi.ac.uk/interpro/api/entry/pfam/PF13699
counters:
  proteins: 5359
  matches: 5421
  proteomes: 2781
  taxa: 4406
  structures: 0
  alphafold_models: 2834
  domain_architectures: 192
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:IPR025295
description: This entry represents a domain found in a group of prokaryotic proteins that was previously
  known as DUF4157. This domain has been recently identified as a highly conserved eCIS (extracellular
  Contractile Injection System) core domain [[cite:PUB00154361]]. eCIS is a cell-free toxin-delivery system
  that evolved from a bacteriophage tail and is prevalent in prokaryotes. This eCIS core DUF4157 domain
  contains an HEXXH motif that is characteristic of many families of metallopeptidases and a putative
  metal-binding site for a divalent cation such as zinc. Proteobacterial members of this family are thought
  to be related to the type VI secretion system (T6SS). This region is responsible for the toxicity of
  the protein in the bacterial periplasm [[cite:PUB00100134]]. eCIS-associated toxins carry DUF4157 domains
  in their N-terminus or are found adjacent to genes with this domain [[cite:PUB00154361]]. No peptidase
  activity has been reported for this domain so far.