By employing a derivative E box that binds ZEB but not E2A , we have shown that the repressor is active in B cells and the IgH enhancer is silenced in the absence of binding competition by bHLH proteins .
by employing a derivative e box that binds zeb but not e2a , we have shown that the repressor is active in b cells and the igh enhancer is silenced in the absence of binding competition by bhlh proteins .
O O O O B-DNA_domain_or_region I-DNA_domain_or_region O O B-protein_molecule O O B-protein_molecule O O O O O O B-protein_family_or_group O O O B-cell_type I-cell_type O O B-DNA_domain_or_region I-DNA_domain_or_region O O O O O O O O O B-protein_family_or_group I-protein_family_or_group O