In contrast , addition of either ligand or antagonist in combination with a heat activation step promoted DNA binding by approximately 3-fold over that of heat-activated unliganded receptors .
in contrast , addition of either ligand or antagonist in combination with a heat activation step promoted dna binding by approximately 3-fold over that of heat-activated unliganded receptors .
O O O O O O O O O O O O O O O O O B-other_name I-other_name O O O O O O O B-protein_family_or_group I-protein_family_or_group O