Uroporphyrinogen-III C-methyltransferase

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 chemical reaction

2 S-adenosyl-L-methionine + uroporphyrinogen III ${\displaystyle \rightleftharpoons }$ 2 S-adenosyl-L-homocysteine + precorrin-2 (overall reaction)

(1a) S-adenosyl-L-methionine + uroporphyrinogen III ${\displaystyle \rightleftharpoons }$ S-adenosyl-L-homocysteine + precorrin-1

(1b) S-adenosyl-L-methionine + precorrin-1 ${\displaystyle \rightleftharpoons }$ S-adenosyl-L-homocysteine + precorrin-2

uroporphyrinogen III substrate of the enzyme

precorrin-2 product of the enzyme

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
Search PMC articles PubMed articles NCBI proteins

Uroporphyrinogen-III C-methyltransferase catalyses two methylation reactions. The first reaction converts uroporphyrinogen III into precorrin-1. The second converts precorrin-1 into precorrin-2. These reactions are part of the biosynthetic pathway to cobalamin (vitamin B₁₂) in both anaerobic and aerobic bacteria.

See also

• Cobalamin biosynthesis