| Uroporphyrinogen-III C-methyltransferase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 2.1.1.107 | ||||||||
| CAS no. | 125752-76-3 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Uroporphyrinogen-III C-methyltransferase (EC 2.1.1.107), uroporphyrinogen methyltransferase, uroporphyrinogen-III methyltransferase, adenosylmethionine-uroporphyrinogen III methyltransferase, S-adenosyl-L-methionine-dependent uroporphyrinogen III methylase, uroporphyrinogen-III methylase, SirA, CysG, CobA, uroporphyrin-III C-methyltransferase, S-adenosyl-L-methionine:uroporphyrin-III C-methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:uroporphyrinogen-III C-methyltransferase. [1] [2] [3] This enzyme catalyses the following overall chemical reaction
The enzyme catalyses two methylation reactions. The first reaction converts uroporphyrinogen III into precorrin-1 and the second forms dihydrosirohydrochlorin (precorrin-2). In both cases the methyl group comes from the cofactor, S-adenosyl methionine (SAM), which loses its methyl group and becomes S-adenosyl-L-homocysteine (SAH). [4] These reactions are part of the biosynthetic pathway to cobalamin (vitamin B12) in both anaerobic and aerobic bacteria. [5]