This polymorphism at residue 57 is a recurrent feature of HLA-DQ evolution , occurring in multiple distinct allelic families , which implies a functional selection for maintaining variation at this position in the class II molecule .
this polymorphism at residue 57 is a recurrent feature of hla-dq evolution , occurring in multiple distinct allelic families , which implies a functional selection for maintaining variation at this position in the class ii molecule .
O B-other_name O B-amino_acid_monomer I-amino_acid_monomer O O O O O B-peptide O O O O O O B-other_name I-other_name O O O O O O O O O O O O O O B-protein_family_or_group I-protein_family_or_group I-protein_family_or_group O