We propose that the requirement for precise spacing of the muA and muB elements is due in part to a directed DNA bend induced by PU . 1 .
we propose that the requirement for precise spacing of the mua and mub elements is due in part to a directed dna bend induced by pu . 1 .
O O O O O O O O O O O O O O O O O O O O O B-DNA_substructure I-DNA_substructure O O B-protein_molecule I-protein_molecule I-protein_molecule O