We found that the R-responsive element is composed of four protoenhancers that span the whole B domain .
we found that the r-responsive element is composed of four protoenhancers that span the whole b domain .
O O O O B-DNA_family_or_group I-DNA_family_or_group O O O O B-DNA_family_or_group O O O O B-DNA_domain_or_region I-DNA_domain_or_region O