Which vitamin is essential for metabolism of sulphur containing amino acids?

ANSWER: (B) Folic acidREF: Lehninger Principles of Biochemistry 4th ed page 674Repeat from Primary DNB CET December 2011Methionine, cysteine,, homocysteine, and taurine are the 4 common sulfur-containing amino acids, but only the first 2 are incorporated into protein.Methionine synthase catalyzes the final step in the regeneration of methionine from homocysteine. Methionine synthase contains the cofactor methylcobalamin (MeB12) and uses the substrates N5-methyl-tetrahydrofolate (N5- mTHF, or levomefolic acid) and homocysteine.Note:While both folic acid and vitamin B12 are involved in sulphur containing amino acid metabolism, vitamin B12 acts as cofactor and Folate acts as substrate.Thiamine and biotin are two sulphur containing vitamins