DNA sequence recognition by NF kappa B p50 homodimer: strict and obscure recognition sites in the binding sequence.
5-Formyl- and 5-(formylmethyl)-2'-deoxyuridines are introduced into a kappa B site instead of thymidine(s) in order to understand target sequence specificity of NF kappa B. It was found that one thymidine in the kappa B site is particularly important for the sequence specific recognition by NF kappa B.