Redox-Linked Structural Changes in Ribonucleotide Reductase

Redox-linked structural changes in ribonucleotide reductase.

Ribonucleotide reductase (RNR) catalyzes the reduction of ribonucleotides to deoxyribonucleotides. Class I RNRs are composed of two homodimeric proteins, alpha2 and beta2. The class Ia E. coli beta2 contains dinuclear, antiferromagnetically coupled iron centers and one tyrosyl free radical, Y122*/beta2. Y122* acts as a radical initiator in catalysis. Redox-linked conformational changes may acco...

Redox-linked changes to the hydrogen-bonding network of ribonucleotide reductase β2.

Ribonucleotide reductase (RNR) catalyzes conversion of nucleoside diphosphates (NDPs) to 2'-deoxynucleotides, a critical step in DNA replication and repair in all organisms. Class-Ia RNRs, found in aerobic bacteria and all eukaryotes, are a complex of two subunits: α2 and β2. The β2 subunit contains an essential diferric-tyrosyl radical (Y122O(•)) cofactor that is needed to initiate reduction o...

Structurally dependent redox property of ribonucleotide reductase subunit p53R2.

p53R2 is a newly identified small subunit of ribonucleotide reductase (RR) and plays a key role in supplying precursors for DNA repair in a p53-dependent manner. Currently, we are studying the redox property, structure, and function of p53R2. In cell-free systems, p53R2 did not oxidize a reactive oxygen species (ROS) indicator carboxy-H2DCFDA, but another class I RR small subunit, hRRM2, did. F...

Structural interconversions modulate activity of Escherichia coli ribonucleotide reductase.

Essential for DNA biosynthesis and repair, ribonucleotide reductases (RNRs) convert ribonucleotides to deoxyribonucleotides via radical-based chemistry. Although long known that allosteric regulation of RNR activity is vital for cell health, the molecular basis of this regulation has been enigmatic, largely due to a lack of structural information about how the catalytic subunit (α(2)) and the r...

Ribonucleotide reductase in developing brain.