loop_
    _pdbx_struct_assembly_auth_evidence.id
    _pdbx_struct_assembly_auth_evidence.assembly_id
    _pdbx_struct_assembly_auth_evidence.experimental_support
    _pdbx_struct_assembly_auth_evidence.details
    1 1 'cross-linking'  .
    2 1 'gel filtration' 'Elutes as a dimer'
    3 2 'cross-linking'  .