2ani | pdb_00002ani
Crystal structure of the F127Y mutant of Ribonucleotide Reductase R2 from Chlamydia trachomatis
Structural highlights
Function[RIR2_CHLTR] Provides the precursors necessary for DNA synthesis. Catalyzes the biosynthesis of deoxyribonucleotides from the corresponding ribonucleotides (By similarity). 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 PubMedA recently discovered subgroup of class I ribonucleotide reductase (RNR) found in the infectious bacterium Chlamydia trachomatis (C. trachomatis) was shown to exhibit a high-valent Fe(III)Fe(IV) center instead of the tyrosyl radical observed normally in all class I RNRs. The X-ray structure showed that C. trachomatis WT RNR has a phenylalanine at the position of the active tyrosine in Escherichia coli RNR. In this paper the X-ray structure of variant F127Y is presented, where the tyrosine is restored. Using (1)H- and (57)Fe-ENDOR spectroscopy it is shown, that in WT and variants F127Y and Y129F of C. trachomatis RNR, the Fe(III)Fe(IV) center is virtually identical with the short-lived intermediate X observed during the iron oxygen reconstitution reaction in class I RNR from E. coli. The experimental data are consistent with a recent theoretical model for X, proposing two bridging oxo ligands and one terminal water ligand. A surprising extension of the lifetime of the Fe(III)Fe(IV) state in C. trachomatis from a few seconds to several hours at room temperature was observed under catalytic conditions in the presence of substrate. These findings suggest a possible new role for the Fe(III)Fe(IV) state also in other class I RNR, during the catalytic radical transfer reaction, by which the substrate turnover is started. Structure of the high-valent FeIIIFeIV state in ribonucleotide reductase (RNR) of Chlamydia trachomatis--combined EPR, 57Fe-, 1H-ENDOR and X-ray studies.,Voevodskaya N, Galander M, Hogbom M, Stenmark P, McClarty G, Graslund A, Lendzian F Biochim Biophys Acta. 2007 Oct;1774(10):1254-63. Epub 2007 Jul 17. PMID:17827077[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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