1av8

From Proteopedia

RIBONUCLEOTIDE REDUCTASE R2 SUBUNIT FROM E. COLI

PDB ID 1av8

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Structural highlights

1av8 is a 2 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.8Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

RIR2_ECOLI Provides the precursors necessary for DNA synthesis. Catalyzes the biosynthesis of deoxyribonucleotides from the corresponding ribonucleotides. R2 contains the tyrosyl radical required for catalysis.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Ribonucleotide reductase (RNR) from Escherichia coli catalyzes the conversion of ribonucleotides to deoxyribonucleotides. It is composed of two homodimeric subunits, R1 and R2. R2 contains the diferric-tyrosyl radical cofactor essential for the nucleotide reduction process. The in vitro mechanism of assembly of this cluster starting with apo R2 or with a diferrous form of R2 has been examined by time-resolved physical biochemical methods. An intermediate, Fe3+/Fe4+ cluster (intermediate X), has been identified that is thought to be directly involved in the oxidation of Y122 to the tyrosyl radical (*Y122). An R2 mutant in which phenylalanine has replaced Y122 has been used to accumulate intermediate X at sufficient levels that it can be studied using a variety of spectroscopic methods. The details of the reconstitution of the apo and diferrous forms of Y122F R2 have been examined by stopped-flow UV/vis spectroscopy and by rapid freeze quench electron paramagnetic resonance, and Mossbauer spectroscopies. In addition the structure of this mutant, crystallized at pH 7.6 in the absence of mercury, at 2.46 A resolution has been determined. These studies suggest that Y122F R2 is an appropriate model for the examination of intermediate X in the assembly process. Studies with two mutants, Y356F and double mutant Y356F and Y122F R2, are interpreted in terms of the possible role of Y356 in the putative electron transfer reaction between the R1 and R2 subunits of this RNR.

Characterization of Y122F R2 of Escherichia coli ribonucleotide reductase by time-resolved physical biochemical methods and X-ray crystallography.,Tong W, Burdi D, Riggs-Gelasco P, Chen S, Edmondson D, Huynh BH, Stubbe J, Han S, Arvai A, Tainer J Biochemistry. 1998 Apr 28;37(17):5840-8. PMID:9558317^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Tong W, Burdi D, Riggs-Gelasco P, Chen S, Edmondson D, Huynh BH, Stubbe J, Han S, Arvai A, Tainer J. Characterization of Y122F R2 of Escherichia coli ribonucleotide reductase by time-resolved physical biochemical methods and X-ray crystallography. Biochemistry. 1998 Apr 28;37(17):5840-8. PMID:9558317 doi:10.1021/bi9728811