Family

Adenylyltransferase and sulfurtransferase MOCS3/Uba4 (IPR028885)

Short name: MOCS3/Uba4

Overlapping homologous superfamilies

Family relationships

None.

Description

This entry includes adenylyltransferase and sulfurtransferase MOCS3 and its homologue, Uba4, from yeasts.

In budding yeasts, Uba4 receives sulphur from Nfs1 and Tum1 [PMID: 21904977]. Uba4 then forms an acyl adenylate intermediate with the C-terminal of the Urm1 protein, and then forms an acyl disulfide bond between Uba4 Cys397 and the Urm1 C-terminal glycin [PMID: 21904977]. Subsequently, the activated Urm1 acts as a sulphur carrier in the process of eukaryotic transfer RNA (tRNA) thiolation [PMID: 19145231].

MOCS3 plays a central role in 2-thiolation of mcm5S2U at tRNA wobble positions of cytosolic tRNA(Lys), tRNA(Glu) and tRNA(Gln) [PMID: 19017811]. It is also essential during biosynthesis of the molybdenum cofactor [PMID: 15073332, PMID: 15910006]. MOCS3 acts by mediating the C-terminal thiocarboxylation of sulfur carriers Urm1 and MOCS2A (the small subunit of molybdopterin synthase) [PMID: 19145231, PMID: 19151091, PMID: 18491921, PMID: 22453920].

GO terms

Biological Process

GO:0002143 tRNA wobble position uridine thiolation

Molecular Function

GO:0004792 thiosulfate sulfurtransferase activity

Cellular Component

GO:0005829 cytosol

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
HAMAP