Enzymatic activity is tightly regulated so that cellular resources are not wasted by the production of unnecessary components. Allostery is a common mechanism of enzyme regulation that involves sensing whether a modulator is bound at a site distinct from the site of catalysis. The information that the modulator is present must be transmitted through correlated motions to the active site, where depending on the function of the modulator, catalytic activity is either stimulated or inhibited. The goal of this project is to understand the correlated motions that give rise to protein allostery and relate them to protein sequence. To do this, the project will take an unprecedented approach that interfaces advanced X-ray scattering methods with complementary techniques, such as single-particle cryo-electron microscopy, and computational bioinformatics. An integral part of this project is to develop a modern structural biology course that incorporates active learning techniques to equip students with the technical knowledge needed to tackle compelling, interdisciplinary problems of the future. A career-focused seminar series will also be developed to educate STEM undergraduates, graduate students, and postdocs to navigate their career paths and develop creative uses of their education.
An ideal family of enzymes for this study is the ribonucleotide reductase family, which performs a key reaction for all DNA-based life. Because of its importance in central metabolism, these enzymes have evolved multiple levels of complex allostery. To understand how enzyme activity is regulated, single-particle methods will be used to probe correlated motions within equilibrium states defined by small-angle X-ray scattering. Evolutionary correlations of the protein sequences will be determined by statistical methods and tested for significance by diffuse X-ray scattering. Finally, ancestral sequence reconstruction methods will be applied to understand how such allosteric mechanisms emerge and evolve.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
