3uus

Crystal structure of the dATP inhibited E. coli class Ia ribonucleotide reductase complex

spinqualitylabelsall models 3uus, resolution 5.65Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3uus is a 8 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 5.65Å Ligands: DTP, FE Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function RIR1_ECOLI Provides the precursors necessary for DNA synthesis. Catalyzes the biosynthesis of deoxyribonucleotides from the corresponding ribonucleotides. R1 contains the binding sites for both substrates and allosteric effectors and carries out the actual reduction of the ribonucleotide. It also provides redox-active cysteines. Publication Abstract from PubMed 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 (alpha(2)) and the radical-generation subunit (beta(2)) interact. Here we present the first structure of a complex between alpha(2) and beta(2) subunits for the prototypic RNR from Escherichia coli. Using four techniques (small-angle X-ray scattering, X-ray crystallography, electron microscopy, and analytical ultracentrifugation), we describe an unprecedented alpha(4)beta(4) ring-like structure in the presence of the negative activity effector dATP and provide structural support for an active alpha(2)beta(2) configuration. We demonstrate that, under physiological conditions, E. coli RNR exists as a mixture of transient alpha(2)beta(2) and alpha(4)beta(4) species whose distributions are modulated by allosteric effectors. We further show that this interconversion between alpha(2)beta(2) and alpha(4)beta(4) entails dramatic subunit rearrangements, providing a stunning molecular explanation for the allosteric regulation of RNR activity in E. coli. Structural interconversions modulate activity of Escherichia coli ribonucleotide reductase.,Ando N, Brignole EJ, Zimanyi CM, Funk MA, Yokoyama K, Asturias FJ, Stubbe J, Drennan CL Proc Natl Acad Sci U S A. 2011 Dec 27;108(52):21046-51. Epub 2011 Dec 12. PMID:22160671 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribonucleotide reductase 3D structures

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