Function changing mutations in glucocorticoid receptor evolution correlate with their relevance to mode coupling

Abstract

Nonlinear effects in protein dynamics are expected to play role in function, particularly of allosteric nature, by facilitatingenergy transfer between vibrational modes. A recently proposed method focusing on the non-Gaussian shape of the configu-rational population near equilibrium projects this information onto real space in order to identify the aminoacids relevantto function. We here apply this method to three ancestral proteins in glucocorticoid receptor (GR) family and show that themutations that restrict functional activity during GR evolution correlate significantly with locations that are highlighted bythe nonlinear contribution to the near-native configurational distribution. Our findings demonstrate that the analysis ofnonlinear effects in protein dynamics can be harnessed into a predictive tool for functional site determination.