Glutamate 52-β at the α/β subunit interface of Escherichia coli class Ia ribonucleotide reductase is essential for conformational gating of radical transfer.

ABSTRACT: Ribonucleotide reductases (RNRs) catalyze the conversion of nucleoside diphosphate substrates (S) to deoxynucleotides with allosteric effectors (e) controlling their relative ratios and amounts, crucial for fidelity of DNA replication and repair. Escherichia coli class Ia RNR is composed of α and β subunits that form a transient, active α2β2 complex. The E. coli RNR is rate-limited by S/e-dependent conformational change(s) that trigger the radical initiation step through a pathway of 35 Å across the subunit (α/β) interface. The weak subunit affinity and complex nucleotide-dependent quaternary structures have precluded a molecular understanding of the kinetic gating mechanism(s) of the RNR machinery. Using a docking model of α2β2 created from X-ray structures of α and β and co

SUBMITTER: Lin Q 

PROVIDER: S-EPMC5454104 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature