has functional parent dehydroalanine (Ser) modified L-serine residue 3-methoxydehydroalanine 12.0 12.010000228881835938 99.0320281982421875 99.089996337890625 MOD:01922 PSI-MOD none 3-methoxydidehydroalanine C 1 natural 3-methoxydehydroalanine C 4 H 5 N 1 O 2 2-amino-3-methoxyprop-2-enoic acid A protein modification that effectively converts an L-serine residue to 3-methoxydehydroalanine. S