Professor Julián Echave will be giving an informal talk on Tuesday 10 April at 11am in the Small Lecture Theatre at the Department of Statistics.

Title: Protein evolutionary divergence is not random

Abstract

A simple comparison of homologous proteins shows clear patterns of differential conservation/variation at the levels of amino-acid sequence, 3D structure, and protein motions. For instance, the rate of sequence evolution varies among sites; protein structures diverge more at some sites than others, and some protein vibrations are more variable than others. The default explanation of evolutionary patterns is the rather fuzzy concept of “functional importance”: the underlying assumption is that any extra conservation/variability is due to natural selection. However, while selection does indeed shape sequence divergence, the patterns of divergence of structure and motion are mostly shaped by the physics of the response of proteins to random mutations.