What is Methionine?
Methionine ( or ; abbreviated as Met or M) is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CH2SCH3. This amino acid is classified as nonpolar as it has a straight side chain that possess a S-methyl thioether (i.e. C–S–C bonding) at the γ-carbon. It is an essential amino acid in all metazoa. This amino-acid is coded by the initiation codon AUG which also indicates mRNA's coding region where translation into protein begins.