loop_
    _pdbx_struct_assembly_gen.assembly_id
    _pdbx_struct_assembly_gen.asym_id_list
    _pdbx_struct_assembly_gen.oper_expression
      1  A  1
      1  B  1
      2  A  2
      2  B  2
      2  C  2
      3  A  3
      3  B  3
      3  D  3
       
    loop_
    _pdbx_struct_assembly_gen.assembly_id
    _pdbx_struct_assembly_gen.asym_id_list
    _pdbx_struct_assembly_gen.oper_expression
      1  'A,B'    1
      2  'A,B,C'  2
      3  'A,B,D'  3