1jqc

Mn substituted Ribonucleotide reductase R2 from E. Coli oxidized by hydrogen peroxide and hydroxylamine

spinqualitylabelsall models 1jqc, resolution 1.61Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1jqc is a 2 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: HG, MN Related: 1jpr Activity: Ribonucleoside-diphosphate reductase, with EC number 1.17.4.1 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 The di-iron carboxylate proteins constitute a diverse class of non-heme iron enzymes performing a multitude of redox reactions. These reactions usually involve high-valent Fe-oxo species and are thought to be controlled by carboxylate shifts. Owing to their short lifetime, the intermediate structures have so far escaped structural characterization by X-ray crystallography. In an attempt to map the carboxylate conformations available to the protein during different redox states and different ligand environments, we have studied metal-substituted forms of the R2 protein of ribonucleotide reductase from Escherichia coli. In the present work we have solved the crystal structures of Mn-substituted R2 oxidized in two different ways. Oxidation was performed using either nitric oxide or a combination of hydrogen peroxide and hydroxylamine. The two structures are virtually identical, indicating that the oxidation states are the same, most likely a mixed-valent MnII-MnIII centre. One of the carboxylate ligands (D84) adopts a new, so far unseen, conformation, which could participate in the mechanism for radical generation in R2. E238 adopts a bridging-chelating conformation proposed to be important for proper O2 activation but not previously observed in the wild-type enzyme. Probable catalase activity was also observed during the oxidation with H2O2, indicating mechanistic similarities to the di-Mn catalases. Crystal structures of oxidized dinuclear manganese centres in Mn-substituted class I ribonucleotide reductase from Escherichia coli: carboxylate shifts with implications for O2 activation and radical generation.,Hogbom M, Andersson ME, Nordlund P J Biol Inorg Chem. 2001 Mar;6(3):315-23. PMID:11315567 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribonucleotide reductase

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