InterPro domain: IPR033706

This domain is the B12 binding domain of methionine synthase. Methionine synthase binds methylcobalamin (B12), which it uses as an intermediate methyl carrier from methyltetrahydrofolate (CH3H4folate) to homocysteine to yield tetrahydrofolate and L-methionine [ 1 , 2 , 3 ].

1. Cobalamin-dependent methionine synthase: the structure of a methylcobalamin-binding fragment and implications for other B12-dependent enzymes. Curr. Opin. Struct. Biol. 4, 919-29
2. Domain alternation switches B(12)-dependent methionine synthase to the activation conformation. Nat. Struct. Biol. 9, 53-6
3. Coenzyme B12 (cobalamin)-dependent enzymes. Essays Biochem. 34, 139-54