id: Pfam:PF04020
pfam_id: PF04020
name: Mycobacterial 4 TMS phage holin, superfamily IV
short_name: Phage_holin_4_2
seed_status: EX_DUF
characterization_status: UNSCORED
curation_status: SEEDED
source_url: https://www.ebi.ac.uk/interpro/api/entry/pfam/PF04020
counters:
  proteins: 11066
  matches: 11066
  proteomes: 8954
  taxa: 12231
  structures: 0
  alphafold_models: 6793
  domain_architectures: 8
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:IPR007165
description: These proteins are predicted transmembrane proteins with probably four transmembrane spans.
  The 1.E.40 is represented by the mycobacterial 4 phage holin, but it also contains many cyanobacterial.
  proteobacterial and firmicute proteins. Holins are encoded within the genomes of Gram-positive and Gram-negative
  bacteria as well as in those of the bacteriophage of these organisms. The primary function of holins
  appears to be transport of murein hydrolases across the cytoplasmic membrane to the cell wall where
  these enzymes hydrolyse the cell wall polymer as a prelude to cell lysis. When chromosomally encoded
  the enzymes are therefore autolysins. Holins may also facilitate leakage of electrolytes and nutrients
  from the cell cytoplasm, thereby promoting cell death. Some may catalyse export of nucleases.