id: Pfam:PF04446
pfam_id: PF04446
name: tRNAHis guanylyltransferase
short_name: Thg1
seed_status: EX_DUF
characterization_status: UNSCORED
curation_status: SEEDED
source_url: https://www.ebi.ac.uk/interpro/api/entry/pfam/PF04446
counters:
  proteins: 4888
  matches: 5546
  proteomes: 3738
  taxa: 9628
  structures: 16
  alphafold_models: 3998
  domain_architectures: 102
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:IPR024956
description: The Thg1 protein from Saccharomyces cerevisiae is responsible for adding a GMP residue to
  the 5' end of tRNA His [[cite:PUB00020433]]. The catalytic domain Thg1 contains a RRM (ferredoxin) fold
  palm domain, just like the viral RNA-dependent RNA polymerases, reverse transcriptases, family A and
  B DNA polymerases, adenylyl cyclases, diguanylate cyclases (GGDEF domain) and the predicted polymerase
  of the CRISPR system [[cite:PUB00057251]]. Thg1 possesses an active site with three acidic residues
  that chelate Mg++ cations [[cite:PUB00057251]]. Thg1 catalyzes polymerization similar to the 5'-3' polymerases
  [[cite:PUB00057251]][[cite:PUB00057252]].