An enzyme that catalyzes the formation of methionine by transfer of a methyl group from 5-methyltetrahydrofolate to homocysteine. It requires a cobamide coenzyme. The enzyme can act on mono- or triglutamate derivatives. EC 2.1.1.13.

Synonyms: 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase, Vitamin B12-Independent Methionine Synthase, S-Methyltransferase, 5-Methyltetrahydrofolate-Homocysteine, Homocysteine Methyltransferase, Methyltetrahydrofolate, Tetrahydropteroylglutamate Methyltransferase, Synthase, Methionine, Methyltransferase, Methyltetrahydrofolate Homocysteine, Vitamin B12-Dependent Methionine Synthase, 0, Methionine Synthase, Methyltransferase, Tetrahydropteroylglutamate, Methionine Synthetase, 5-Methyltetrahydropteroyltri-L-glutamate:L-homocysteine S-methyltransferase, EC 2.1.1.13, Methyltetrahydrofolate Homocysteine Methyltransferase, Synthetase, Methionine