[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is an alpha-amino acid zwitterion that is O-acetylhomoserine in which a proton has been transferred from the carboxy group to the amino group. It is the major species at pH 7.3. It is a tautomer of an O-acetylhomoserine."}, {"from": "gpt", "value": "[C][C][=Branch1][C][=O][O][C][C][C][Branch1][=Branch1][C][=Branch1][C][=O][O-1][NH3+1]"}]