1biq

RIBONUCLEOSIDE-DIPHOSPHATE REDUCTASE 1 BETA CHAIN MUTANT E238A

spinqualitylabelsall models 1biq, resolution 2.05Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1biq 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 2.05Å Ligands: FE, FE2, HG, MTY, OH 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 R2 protein of ribonucleotide reductase catalyzes the dioxygen-dependent one-electron oxidation of Tyr122 at a diiron-carboxylate site. Methane monooxygenase and related hydroxylases catalyze hydrocarbon hydroxylation at diiron sites structurally related to the one in R2. In protein R2, the likely reaction site for dioxygen is close to Phe208. The crystal structure of an iron ligand mutant R2, Y122F/E238A, reveals the hydroxylation of Phe208 at the meta, or epsilon-, ring position and the subsequent coordination of this residue to the diiron site. In another mutant, F208Y, the "foreign" residue Tyr208 is hydroxylated to Dopa. The structures of apo and diferrous F208Y presented here suggest that Tyr208 is coordinated to the iron site of F208Y throughout the Dopa generation cycle. Together, the structural data on these two mutants suggest two possible reaction geometries for the hydroxylation reaction catalyzed by these modified R2 diiron sites, geometries which might be relevant for the hydroxylation reaction catalyzed by other diiron sites such as methane monooxygenase. A critical role for residue Glu238 in directing the oxidative power of the reactive intermediate toward oxidation of Tyr122 is proposed. Crystal structures of two self-hydroxylating ribonucleotide reductase protein R2 mutants: structural basis for the oxygen-insertion step of hydroxylation reactions catalyzed by diiron proteins.,Logan DT, deMare F, Persson BO, Slaby A, Sjoberg BM, Nordlund P Biochemistry. 1998 Jul 28;37(30):10798-807. PMID:9692970 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribonucleotide reductase 3D structures

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