thiH (P30140) notes, E. coli K-12

Deep research was unavailable for this gene (falcon 403, asta returned nothing in Phase 1
of the RADICAL_SAM project). Notes are built from cached publications, PubMed and UniProt.

Identity

• UniProt P30140, 2-iminoacetate synthase (tyrosine lyase, dehydroglycine synthase),
  EC 4.1.99.19, b3990, last gene of thiCEFSGH. Radical SAM superfamily, ThiH family
  (TIGR02351, IPR012726), with a C-terminal BATS domain (shared with HydG/NosL).
  One radical SAM [4Fe-4S] cluster (Cys85/89/92). Heterodimer with ThiG (P30139)
  [file:ECOLI/thiH/thiH-uniprot.txt].

Which subunit does what

• ThiH (radical SAM) cleaves the Calpha-Cbeta bond of L-tyrosine to dehydroglycine
  (2-iminoacetate) and p-cresol, consuming SAM to 5'-dA + Met
  PMID:19923213.
• ThiG (thiazole synthase, GO:1990107) condenses dehydroglycine with DXP and ThiS
  thiocarboxylate to form the thiazole phosphate
  PMID:17403671.
• ThiG and ThiH co-purify as a complex PMID:12650933;
  described as an alpha-beta heterodimer PMID:19923213.
  ThiH has been studied only as the ThiGH complex, so the GO complex term
  GO:1902508 2-iminoacetate synthase complex fits (ThiG also carries it in GOA).
  ThiH should NOT get thiazole synthase activity (that is ThiG); the complex could equally
  be called the thiazole synthase complex (GO:1902507), which GOA does not use for either
  subunit.
• [4Fe-4S] cluster reconstitution essential; SAM binds the cluster
  PMID:17403671.
• Catalytic (multiple turnover) tyrosine lyase with product inhibition by 5'-dA (PMID:19923213).
• In aerobes (B. subtilis) ThiO glycine oxidase replaces ThiH; module
  thiamine_diphosphate_biosynthesis models this as alternative dehydroglycine routes.

Genetics

• thiH required for thiazole synthesis PMID:8432721.
• DNA damage response (PMID:11967071): mitomycin C microarray expression change; not a function.

Curation decisions

• GO:1904047 SAM binding absent from GOA; added as NEW (IDA, PMID:17403671).
• Iron ion binding (GO:0005506): lateral MODIFY to GO:0051539, as for GO:0046872 under the
  RADICAL_SAM treatment rule; ThiH has no separate iron site.
• Protein binding (ThiG) REMOVE as uninformative; the ThiGH association is captured by
  GO:1902508.