Glutamate Mediates Proton-Coupled Electron Transfer Between Tyrosines 730 and 731 in Escherichia coli Ribonucleotide Reductase.

ABSTRACT: Ribonucleotide reductase (RNR) is an essential enzyme in DNA synthesis for all living organisms. It reduces ribonucleotides to the corresponding deoxyribonucleotides by a reversible radical transfer mechanism. The active form of E. coli Ia RNR is composed of two subunits, α and β, which form an active asymmetric α₂β₂ complex. The radical transfer pathway involves a series of proton-coupled electron transfer (PCET) reactions spanning α and β over ∼32 Å. Herein, quantum mechanical/molecular mechanical free energy simulations of PCET between tyrosine residues Y730 and Y731 are performed on the recently solved cryo-EM structure of the active α₂β₂ complex, which includes a pre-turnover α/β pair with an ordered PCET pathway and a post-turnover α

SUBMITTER: Reinhardt CR 

PROVIDER: S-EPMC8500205 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature