The ability of mutants to activate a reporter gene under the control of MHC class II conserved W-X-Y or X-Y regulatory elements was determined .
the ability of mutants to activate a reporter gene under the control of mhc class ii conserved w-x-y or x-y regulatory elements was determined .
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 O O O O O O O O