We apologize for Proteopedia being slow to respond. For the past two years, a new implementation of Proteopedia has been being built. Soon, it will replace this 18-year old system. All existing content will be moved to the new system at a date that will be announced here.

1mrr

From Proteopedia

Jump to: navigation, search

SUBSTITUTION OF MANGANESE FOR IRON IN RIBONUCLEOTIDE REDUCTASE FROM ESCHERICHIA COLI. SPECTROSCOPIC AND CRYSTALLOGRAPHIC CHARACTERIZATION

Structural highlights

1mrr 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 2.5Å
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

Each polypeptide chain of protein R2, the small subunit of ribonucleotide reductase from Escherichia coli, contains a stable tyrosyl radical and two antiferromagnetically coupled oxo-bridged ferric ions. A refined structure of R2 has been recently obtained. R2 can be converted into apoR2 by chelating out the metal cofactor and scavenging the radical. This study shows that apoR2 has a very strong affinity for four stable Mn2+ ions. The manganese-containing form of R2, named Mn-R2, has been studied by EPR spectroscopy and x-ray crystallography. It contains two binuclear manganese clusters in which the two manganese ions occupy the natural iron-binding sites and are only bridged by carboxylates from glutamates 115 and 238. This in turn explains why the spin-exchange interaction between the two ions is very weak and why Mn-R2 is EPR active. Mn-R2 could provide a model for the native diferrous form of protein R2, and a detailed molecular mechanism for the reduction of the iron center of protein R2 is proposed.

Substitution of manganese for iron in ribonucleotide reductase from Escherichia coli. Spectroscopic and crystallographic characterization.,Atta M, Nordlund P, Aberg A, Eklund H, Fontecave M J Biol Chem. 1992 Oct 15;267(29):20682-8. PMID:1328209^[1]

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

References

↑ Atta M, Nordlund P, Aberg A, Eklund H, Fontecave M. Substitution of manganese for iron in ribonucleotide reductase from Escherichia coli. Spectroscopic and crystallographic characterization. J Biol Chem. 1992 Oct 15;267(29):20682-8. PMID:1328209