Slow protein dynamics probed by NMR: at the heart of protein evolvability

BARH, GUILLERMO; GONZALEZ MARIANO; VILA, A J; GONZALEZ, L

Grosseto

Workshop; Chianti Workshop ?Magnetic Resonance for Cellular Structural Biology?; 2016

Theunderstanding of protein evolution depends on the ability to relate the impactof mutations on molecular traits to fitness at the cellular level. Biologicalactivity and stability are key features in shaping protein evolutionarylandscapes. Instead, conformational dynamics, has been thoroughly studied atthe molecular level, but the impact of dynamics in evolution has not beentraced to the cellular level. We have used NMR to study the intrinsic dynamicfeatures of a metallo-β-lactamase enzyme along a defined evolutionary pathwayin which optimization of the enzyme performance is due to augmented dynamicfeatures, resulting in a neat phenotype, i.e. cell survival. We can also assessthe interaction of these mutations along evolution, and identify how someevolutionary pathways are preferred. Optimization of protein dynamics, however,entails a loss of stability, which in some cases, asks for compensatoryeffects. We have also analyzed a series of metallo-β-lactamase variants inwhich metal binding plays a stabilizing, compensatory role, restrictingdynamics and preventing protein degradation within the cell. Overall,we can correlate the NMR-based description of protein dynamics at an atomisticlevel to cell survival under certain conditions. References1.     Tokuriki N,Tawfik DS. Science. 324,203-7 (2009).2.    González MM, AbriataLA, Tomatis PE, Vila AJ.Mol Biol Evol.(2016) doi:10.1093/molbev/msw052