loop_ _pdbx_chem_comp_identifier.comp_id _pdbx_chem_comp_identifier.identifier _pdbx_chem_comp_identifier.type _pdbx_chem_comp_identifier.program _pdbx_chem_comp_identifier.program_version ATP "adenosine 5'-(tetrahydrogen triphosphate)" "SYSTEMATIC NAME" ACDLabs 10.04