Thermodynamics of Interactions of Escherichia Coli HU[alpha, Beta] with Duplex DNA

Parallel ITC studies with IHF demonstrate the same three nonspecific binding modes and analogous transitions between them. Distinct thermodynamic and structural differences between nonspecific 34 bp binding modes of IHF and HU are observed. The 34 bp mode of IHF, in contrast to that of HU, is proposed to involve both bending and wrapping of DNA around the protein body and subsequent coupled disruptions of salt bridges on the protein surface.