The enzyme methylmalonyl-CoA mutase is a member of a class of enzymes that uses coenzyme B12 (adenosylcobalamin) as a cofactor. The enzyme induces the formation of an adenosyl radical from the cofactor. This radical then initiates a free-radical rearrangement of its substrate, succinyl-CoA, to methylmalonyl-CoA.
Jiyao W et al.(2023). "The conserved domain database in 2023.",