MOCOS: Molybdenum Cofactor Sulfurase
Key enzyme in molybdenum cofactor sulfuration and purine metabolism
Gene Information Card
| Symbol | MOCOS |
|---|---|
| Full Name | Molybdenum Cofactor Sulfurase |
| Gene Type | Protein-coding |
| Chromosomal Location | 18q12.2 |
| NCBI Gene ID | 55034 ncbi.nlm.nih.gov/gene/55034 |
| Ensembl ID | ENSG00000101473 |
| UniProt ID | Q96EN8 |
| OMIM ID | 613274 |
| HGNC ID | 18259 |
| Aliases | MCS, molybdenum cofactor sulfurase, hMCS |
Description
The MOCOS gene encodes molybdenum cofactor sulfurase, an enzyme that catalyzes the sulfuration of the molybdenum cofactor (Moco). This modification is essential for the activity of molybdenum-dependent enzymes such as xanthine dehydrogenase (XDH) and aldehyde oxidase (AOX1). MOCOS deficiency leads to xanthinuria type II, characterized by impaired purine metabolism and elevated urinary xanthine and hypoxanthine.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Xanthinuria type II | Loss-of-function mutations in MOCOS impair Moco sulfuration, inactivating XDH and AOX1, leading to accumulation of xanthine and hypoxanthine. | OMIM #603592; ClinVar; PMID: 17924339 |
| Hereditary xanthinuria | MOCOS mutations cause type II xanthinuria, distinguished from type I by additional AOX1 deficiency. | OMIM #603592; PMID: 17924339 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.3 | Medium |
| Kidney | 8.7 | Medium |
| Small intestine | 6.5 | Medium |
| Adipose tissue | 4.2 | Low |
| Lung | 2.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 10.5 | Hepatocellular carcinoma cell line |
| HEK293 | 7.8 | Embryonic kidney cells |
| Caco-2 | 5.9 | Colorectal adenocarcinoma cells |
| A549 | 3.2 | Lung carcinoma cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.245G>A (p.Arg82Gln) | Missense | Rare | Loss of function; associated with xanthinuria type II |
| c.1012C>T (p.Arg338*) | Nonsense | Rare | Premature stop; loss of function |
| c.1666C>T (p.Arg556Trp) | Missense | Rare | Loss of function; reduced enzyme activity |
Mutation functional classification
Loss of Function (LOF)
Most reported MOCOS mutations are loss-of-function, leading to reduced or absent sulfuration of Moco, causing xanthinuria type II.
Gain of Function (GOF)
No gain-of-function mutations have been described for MOCOS.
Dominant Negative (DN)
No dominant-negative mutations have been reported for MOCOS.
View complete mutation data：
Gene Ontology (GO)
| • catalytic activity (GO:0003824) | • Mo-molybdopterin cofactor biosynthetic process (GO:0006777) |
| • sulfurtransferase activity (GO:0016783) | • cytoplasm (GO:0005737) |
| • cytosol (GO:0005829) |
Pathways
• Molybdenum cofactor biosynthesis (Reactome: R-HSA-947581)
• Purine metabolism (KEGG: hsa00230)
• Caffeine metabolism (KEGG: hsa00232)
Protein Summary
Molybdenum cofactor sulfurase (MOCOS) is a 888-amino acid cytoplasmic enzyme that catalyzes the transfer of sulfur to the molybdenum cofactor (Moco). This sulfuration step is required for the maturation of xanthine dehydrogenase (XDH) and aldehyde oxidase (AOX1). The protein contains a N-terminal rhodanese-like domain and a C-terminal domain involved in Moco binding. Defects in MOCOS result in xanthinuria type II, a rare autosomal recessive disorder characterized by low uric acid and high xanthine/hypoxanthine levels in urine.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MOCOS Knockout HEK293 Cell Line | EDJ-KQ13495 | Human | 55034 | Details Get a Quote |
| MOCOS Knockout A-549 Cell Line | EDJ-KQ44322 | Human | 55034 | Details Get a Quote |
| MOCOS Knockout HCT 116 Cell Line | EDJ-KQ44323 | Human | 55034 | Details Get a Quote |
| MOCOS Knockout HeLa Cell Line | EDJ-KQ44324 | Human | 55034 | Details Get a Quote |
