Base-pair substitutions in the TF site indicated that the presence of a cytosine at position 1 precluded binding of NF-kappa B .
base-pair substitutions in the tf site indicated that the presence of a cytosine at position 1 precluded binding of nf-kappa b .
O O O O B-protein_family_or_group O O O O O O O B-amino_acid_monomer O B-protein_domain_or_region I-protein_domain_or_region O O O B-protein_molecule I-protein_molecule O