ID   2.1.1.13
DE   Methionine synthase.
AN   5-methyltetrahydrofolate--homocysteine S-methyltransferase.
AN   5-methyltetrahydrofolate--homocysteine transmethylase.
AN   B12 N(5)-methyltetrahydrofolate homocysteine methyltransferase.
AN   Cobalamin-dependent methionine synthase.
AN   Methionine synthase (cobalamin-dependent).
AN   Methionine synthetase.
AN   Methyltetrahydrofolate--homocysteine vitamin B12 methyltransferase.
AN   N(5)-methyltetrahydrofolate methyltransferase.
AN   N(5)-methyltetrahydrofolate--homocysteine cobalamin methyltransferase.
AN   N(5)-methyltetrahydrofolic--homocysteine vitamin B12 transmethylase.
AN   N-methyltetrahydrofolate:L-homocysteine methyltransferase.
AN   Tetrahydrofolate methyltransferase.
AN   Tetrahydropteroylglutamate methyltransferase.
AN   Tetrahydropteroylglutamic methyltransferase.
AN   Vitamin B12 methyltransferase.
CA   5-methyltetrahydrofolate + L-homocysteine = tetrahydrofolate +
CA   L-methionine.
CF   Cobalamin; Zinc.
CC   -!- The enzyme becomes inactivated occasionally during its cycle by
CC       oxidation of Co(I) to Co(II).
CC   -!- Reactivation by reductive methylation is catalyzed by the enzyme
CC       itself, with S-adenosyl-L-methionine as the methyl donor and a
CC       reducing system.
CC   -!- For the mammalian enzyme, the reducing system involves NADPH and
CC       EC 1.16.1.8.
CC   -!- In bacteria, the reducing agent is flavodoxin, and no further
CC       catalyst is needed (the flavodoxin is kept in the reduced state by
CC       NADPH and EC 1.18.1.2).
CC   -!- Acts on the monoglutamate as well as the triglutamate folate,
CC       in contrast with EC 2.1.1.14, which acts only on the triglutamate.
PR   PROSITE; PDOC50972;
DR   Q4JIJ3, METH_BOVIN ;  A8XY95, METH_CAEBR ;  Q09582, METH_CAEEL ;
DR   Q54P92, METH_DICDI ;  P13009, METH_ECOLI ;  Q99707, METH_HUMAN ;
DR   A6H5Y3, METH_MOUSE ;  Q49775, METH_MYCLE ;  O33259, METH_MYCTU ;
DR   Q9I2Q2, METH_PSEAE ;  O33465, METH_PSEPU ;  Q9Z2Q4, METH_RAT   ;
DR   P37586, METH_SALTY ;  Q55786, METH_SYNY3 ;  Q9KUW9, METH_VIBCH ;
DR   Q5E814, METH_VIBF1 ;  Q9AJQ8, METH_VIBFI ;  Q87L95, METH_VIBPA ;
DR   Q8DCJ7, METH_VIBVU ;  Q7MHB1, METH_VIBVY ;
//