Protein Variants | Comment | Organism |
---|---|---|
additional information | construction of a homozygous MOCS3 knockout in HEK293T cells using the CRISPR/Cas9 system. The sulfite oxidase activity in the heterozygous (+/-) MOCS3 cell line is not affected, still containing one functional allele for MOCS3. The low levels of MOCS3 present in the (+/-) cells are sufficient to maintain the levels of sulfite oxidase activity. The sulfite oxidase activity of the homozygous (-/-) MOCS3 knockout can be rescued by reintroducing the MOCS3 protein, which results in an 80% increase in activity. Separate introduction of the N-terminal MOCS3 MoeB-like domain or only the C-terminal MOCS3 rhodanese-like domain does not result in a detectable increase in sulfite oxidase activity. In the heterozygous MOCS3 knockout cell line, a small amount of the mcm5U precursor is detected, while it is undetectable in wild-type HEK293T cells. This low level of accumulation of the mcm5U precursor might be based on the low levels of MOCS3 in the (+/-) cells that are sufficient to maintain almost the levels of the modified mcm5s2U as wild-type levels. No significant effect of the absence of MOCS3 on isocitrate dehydrogenase (ICDH) activity, while aconitase activities are reduced. MOCS3 does not seem to impact the cytosolic localization of NFS1 | Homo sapiens |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Homo sapiens |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + [molybdopterin-synthase sulfur-carrier protein]-Gly-Gly | Homo sapiens | - |
diphosphate + [molybdopterin-synthase sulfur-carrier protein]-Gly-Gly-AMP | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | O95396 | - |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
HEK-293T cell | - |
Homo sapiens | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + [molybdopterin-synthase sulfur-carrier protein]-Gly-Gly | - |
Homo sapiens | diphosphate + [molybdopterin-synthase sulfur-carrier protein]-Gly-Gly-AMP | - |
? |
Synonyms | Comment | Organism |
---|---|---|
MOCS3 | - |
Homo sapiens |
molybdenum cofactor synthesis protein 3 | UniProt | Homo sapiens |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
assay at | Homo sapiens |
General Information | Comment | Organism |
---|---|---|
malfunction | in homozygous MOCS3-knockout HEK293T cells, sulfite oxidase activity is almost completely abolished, on the basis of the absence of Moco in these cells. In addition, mcm5s2U thio-modified tRNAs are not detectable. Impact of a MOCS3 knockout on the cellular localization of NFS1, MOCS3-independent localization of NFS1 (a L-cysteine desulfurase NFS1 acting as a sulfur donor for MOCS3 in the cytosol) at the tips of the centrosome | Homo sapiens |
physiological function | human MOCS3 is a dual-function protein that plays an important role in Moco biosynthesis and in the mcm5s2U thio modifications of nucleosides in cytosolic tRNAs for Lys, Gln, and Glu. Cellular roles of MOCS3, overview. MOCS3 is involved in mcm5s2U34 tRNA modifications in the cytosol by forming a thiocarboxylate group on URM1, which is further used as sulfur-providing protein for the tRNA nucleoside modification. The overall cytosolic levels of the mcm5s2U modification seem to be very low | Homo sapiens |