HGNC Approved Gene Symbol: MOCS3
Cytogenetic location: 20q13.13 Genomic coordinates (GRCh38) : 20:50,958,818-50,963,929 (from NCBI)
MOCS3 is thought to catalyze both the adenylation and subsequent generation of a thiocarboxylate group at the C terminus of the smaller subunit of molybdopterin synthase, MOCS2A (603708) (Matthies et al., 2004).
Matthies et al. (2004) cloned human MOCS3. The deduced 460-amino acid protein has a calculated molecular mass of 49.7 kD. It contains an N-terminal MoeB domain and a C-terminal rhodanese (TST; 180370)-like domain (RLD). Fluorescence-tagged MOCS3 showed a cytoplasmic distribution in transfected HeLa cells.
Matthies et al. (2004) expressed the C-terminal RLD of MOCS3 in E. coli and found that it catalyzed the transfer of sulfur from thiosulfate to cyanide. In a defined in vitro system for the generation of molybdopterin from a precursor, the sulfurated form of MOCS3-RLD was able to provide the sulfur for the thiocarboxylation of MOCS2A. Mutation of the putative persulfide-forming active site cysteine (cys412) abolished the sulfurtransferase activity.
Matthies et al. (2004) determined that the MOCS3 gene is intronless.
Matthies et al. (2004) stated that the MOCS3 gene maps to chromosome 20.
Matthies, A., Rajagopalan, K. V., Mendel, R. R., Leimkuhler, S. Evidence for the physiological role of a rhodanese-like protein for the biosynthesis of the molybdenum cofactor in humans. Proc. Nat. Acad. Sci. 101: 5946-5951, 2004. [PubMed: 15073332] [Full Text: https://doi.org/10.1073/pnas.0308191101]