Data items in the PDBX_ENTITY_POLY_DOMAIN category specify domains of monomers within a polymer.
_pdbx_entity_poly_domain.begin_mon_id _pdbx_entity_poly_domain.begin_seq_num _pdbx_entity_poly_domain.end_mon_id _pdbx_entity_poly_domain.end_seq_num _pdbx_entity_poly_domain.entity_id _pdbx_entity_poly_domain.id