Cobalt precorrin 7 (C15) methyltransferase (decarboxylating)

Cobalt-precorrin-7 (C¹⁵)-methyltransferase (decarboxylating) (EC 2.1.1.196, CbiT) is an enzyme with systematic name S-adenosyl-L-methionine:precorrin-7 C¹⁵-methyltransferase (C-12-decarboxylating). This enzyme catalyses the following chemical reaction

cobalt-precorrin-7 + S-adenosyl-L-methionine ⇌ cobalt-precorrin-8x + S-adenosyl-L-homocysteine + CO₂

This enzyme catalyses both methylation at C-15 and decarboxylation of the C-12 acetate side chain of cobalt-precorrin-7.