Data items in the PDBX_ENTITY_BRANCH_LIST category specify the list
of monomers in a branched entity. Allowance is made for the possibility
of microheterogeneity in a sample by allowing a given sequence
number to be correlated with more than one monomer ID. The
corresponding ATOM_SITE entries should reflect this
heterogeneity.
loop_
_pdbx_entity_branch_list.entity_id
_pdbx_entity_branch_list.num
_pdbx_entity_branch_list.comp_id
_pdbx_entity_branch_list.hetero
2 1 NAG n
2 2 GAL n
2 3 FUC n
2 4 FUC n