MOCS3

Molybdenum cofactor (MoCo) is necessary for the function of all molybdoenzymes. The protein encoded by this gene adenylates and activates molybdopterin synthase, an enzyme required for biosynthesis of MoCo. This gene contains no introns. A pseudogene of this gene is present on chromosome 14. [provided by RefSeq, Nov 2012]

Molybdenum Cofactor Synthesis 3

Plays a central role in 2-thiolation of mcm5S2U at tRNA wobble positions of cytosolic tRNA(Lys), tRNA(Glu) and tRNA(Gln). Also essential during biosynthesis of the molybdenum cofactor. Acts by mediating the C-terminal thiocarboxylation of sulfur carriers URM1 and MOCS2A. Its N-terminus first activates URM1 and MOCS2A as acyl-adenylates (-COAMP), then the persulfide sulfur on the catalytic cysteine is transferred to URM1 and MOCS2A to form thiocarboxylation (-COSH) of their C-terminus. The reaction probably involves hydrogen sulfide that is generated from the persulfide intermediate and that acts as nucleophile towards URM1 and MOCS2A. Subsequently, a transient disulfide bond is formed. Does not use thiosulfate as sulfur donor; NFS1 probably acting as a sulfur donor for thiocarboxylation reactions.

Mo-molybdopterin cofactor biosynthetic process Source: UniProtKB
Protein urmylation Source: GO_Central
tRNA thio-modification Source: UniProtKB
tRNA wobble position uridine thiolation Source: GO_Central
tRNA wobble uridine modification Source: UniProtKB

Cytoplasm