Backbone dynamics of a winged helix protein and its DNA complex at different temperatures: changes of internal motions in genesis upon binding to DNA.

The dynamic properties of a winged helix protein, Genesis, and its DNA complex at different temperatures were studied. Due to the complexity of motions, the commonly used model-free formalism could not be used to reflect the dynamic properties. The reduced spectral density function mapping approach was proven to be a useful tool to describe the overall and internal motion of molecules on the picosecond to nanosecond time-scale, and conformational exchanges on the microsecond to millisecond time-scale. The local motions in DNA-free Genesis showed strong temperature dependence and the backbone dynamics of each secondary structural element responds to the temperature change differently, while the Genesis-DNA complex showed more stability with changing the temperatures. Furthermore, each DNA contact sequence of Genesis showed distinct dynamic perturbation after Genesis binds to DNA. Copyright 1999 Academic Press.