[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is a dipeptide zwitterion resulting from transfer of a proton from the carboxy to the amino group of L-seryl-L-threonine; major species at pH 7.3. It is a tautomer of a Ser-Thr."}, {"from": "gpt", "value": "[C][C@H1][Branch2][Ring1][Ring2][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][N][C][=Branch1][C][=O][C@H1][Branch1][Ring1][C][O][NH3+1][O]"}]