loop_ _pdbx_reference_entity_link.prd_id _pdbx_reference_entity_link.link_id _pdbx_reference_entity_link.link_class _pdbx_reference_entity_link.ref_entity_id_1 _pdbx_reference_entity_link.entity_seq_num_1 _pdbx_reference_entity_link.comp_id_1 _pdbx_reference_entity_link.atom_id_1 _pdbx_reference_entity_link.ref_entity_id_2 _pdbx_reference_entity_link.entity_seq_num_2 _pdbx_reference_entity_link.comp_id_2 _pdbx_reference_entity_link.atom_id_2 _pdbx_reference_entity_link.value_order _pdbx_reference_entity_link.component_1 _pdbx_reference_entity_link.component_2 PRD_000001 1 PN 1 1 DSN N 2 . QUI C 'single' 1 2 PRD_000001 2 PN 1 5 DSN N 3 . QUI C 'single' 1 3