3n39
From Proteopedia
Ribonucleotide Reductase Dimanganese(II)-NrdF from Escherichia coli in Complex with NrdI
Structural highlights
FunctionRIR4_ECOLI Provides the precursors necessary for DNA synthesis. Catalyzes the biosynthesis of deoxyribonucleotides from the corresponding ribonucleotides. R2F 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 PubMedThe class Ib ribonucleotide reductase of Escherichia coli can initiate reduction of nucleotides to deoxynucleotides with either a Mn(III)(2)-tyrosyl radical (Y*) or a Fe(III)(2)-Y* cofactor in the NrdF subunit. Whereas Fe(III)(2)-Y* can self-assemble from Fe(II)(2)-NrdF and O(2), activation of Mn(II)(2)-NrdF requires a reduced flavoprotein, NrdI, proposed to form the oxidant for cofactor assembly by reduction of O(2). The crystal structures reported here of E. coli Mn(II)(2)-NrdF and Fe(II)(2)-NrdF reveal different coordination environments, suggesting distinct initial binding sites for the oxidants during cofactor activation. In the structures of Mn(II)(2)-NrdF in complex with reduced and oxidized NrdI, a continuous channel connects the NrdI flavin cofactor to the NrdF Mn(II)(2) active site. Crystallographic detection of a putative peroxide in this channel supports the proposed mechanism of Mn(III)(2)-Y* cofactor assembly. Structural Basis for Activation of Class Ib Ribonucleotide Reductase.,Boal AK, Cotruvo JA Jr, Stubbe J, Rosenzweig AC Science. 2010 Aug 5. PMID:20688982[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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