Thermodynamic interaction between cold shock protein from extreme thermophile and single stranded DNA and the three-dimensional structure of their complex

Yoshimura, Naoki*; Sato, Rena*; Adachi, Motoyasu; Kuroki, Ryota; Kato, Etsuko*; Kidokoro, Shunichi*

The change of the thermodynamic functions accompanying the binding of a single stranded oligo-DNA with a sequence of TCTTTTT to cold shock protein from HB8 was evaluated by isothermal titration calorimetry, and the three-dimensional structure of the complex was determined by X-ray crystallography. The binding was almost approximated by a two-state model and found to be stabilized by large negative enthalpy change due to the stacking interaction between the bases of the DNA and the aromatic side chains of the protein.