Abstract and Biography - Nozomi Ando

Abstract

Evolution of an Ancient Allosteric Enzyme

Ribonucleotide reductases (RNRs) are used by all free-living organisms and many viruses to catalyze an essential step in the de novo biosynthesis of DNA precursors.  Although this enzyme family has been diversifying for billions of years, they share a conserved radical-based mechanism for nucleotide reduction that is housed in a conserved structural fold.  In this talk, I will discuss the evolution of this RNR family, which we propose based on large-scale phylogenetic inference and other bioinformatic analyses.  Using structural information from small-angle X-ray scattering (SAXS), crystallography, cryo-electron microscopy (cryo-EM), and structure prediction by AlphaFold, I will describe the loss and gain of allosteric mechanisms as well as the discovery of a new phylogenetically distinct clade with implications on how molecular adaptations to increasing oxygen levels may have appeared on the planet.

Bio-Summary

Dr. Ando received her BS from MIT where she was a physics major and music performance minor. She was drawn to the spaceship-like feel of the Cornell High Energy Synchrotron Source (CHESS) and went to Cornell University for her PhD in physics. As a graduate student in Sol Gruner’s lab, she made her own diamond cells for high-pressure X-ray scattering studies.  She then went on to work as a postdoctoral fellow in Cathy Drennan’s lab at MIT, where she developed a fascination with metalloenzymes.  In 2014, she was appointed Assistant Professor of Chemistry at Princeton University and started a research program that combines X-ray physics and structural enzymology.  In 2018, the Ando lab moved to Cornell University when she joined the faculty in Chemistry & Chemical Biology.  Her research employs a combination of biophysical and biochemical techniques to study enzymes in action, and her lab has established X-ray scattering approaches to understand conformation disorder.  Dr. Ando has received an NIH MIRA award, an NSF CAREER award, and won an Early Career Award from the American Crystallographic Association.