Adenylyltransferase and sulfurtransferase MOCS3 (MOCS3)

The **Adenylyltransferase and sulfurtransferase MOCS3** (MOCS3) is a cytosolic dual-function enzyme essential for the biosynthesis of the molybdenum cofactor (MoCo), a critical cofactor required for all molybdoenzymes—including sulfite oxidase, xanthine dehydrogenase, and aldehyde oxidase. MOCS3 catalyzes adenylation and subsequent thiocarboxylation reactions that activate the small subunit of molybdopterin synthase (MPT synthase) and also mediates 2-thiolation modifications of cytosolic tRNAs (Lys, Glu, Gln). Mutations in MOCS3 can lead to MoCo deficiency, a severe autosomal recessive disorder characterized by deficient activity of all molybdoenzymes and serious metabolic consequences or early childhood death. MOCS3 is not currently targeted by any drugs, but its function is essential for cellular metabolism, and its deficiency serves as a biomarker for related metabolic diseases[1][2][3][6].

Other names

Molybdenum cofactor synthesis protein 3Molybdopterin-synthase adenylyltransferaseMolybdopterin-synthase sulfurtransferaseUBA4MPT synthase sulfurylasedJ914P20.3Sulfur carrier protein MOCS2A adenylyltransferaseSulfur carrier protein MOCS2A sulfurtransferaseSulfurtransferase MOCS3Ubiquitin-like modifier activating enzyme 4Ubiquitin-activating enzyme E1 homolog

Not applicable; no known drugs directly targeting MOCS3 - For MOCS3: catalyzes adenylation and thiocarboxylation in MoCo and tRNA modification, not a current drug target[2][3][5]