Two consensus sequences , called X and Y boxes , capable of binding nuclear proteins and regulating expression in B cells have been defined within the immediate upstream region of major histocompatibility complex ( MHC ) class II promoters .
two consensus sequences , called x and y boxes , capable of binding nuclear proteins and regulating expression in b cells have been defined within the immediate upstream region of major histocompatibility complex ( mhc ) class ii promoters .
O O O O O O O O O O O O O B-protein_family_or_group I-protein_family_or_group O O B-other_name O B-cell_type I-cell_type O O O O O O O O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region O