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dc.contributor.authorZipse, Hendrik
dc.contributor.authorArtin, Erin
dc.contributor.authorWnuk, Stanislaw
dc.contributor.authorLohman, Gregory J. S.
dc.contributor.authorMartino, Debora
dc.contributor.authorGriffin, Robert Guy
dc.date.accessioned2012-10-18T17:11:49Z
dc.date.available2012-10-18T17:11:49Z
dc.date.issued2008-12
dc.date.submitted2008-08
dc.identifier.issn0002-7863
dc.identifier.issn1520-5126
dc.identifier.urihttp://hdl.handle.net/1721.1/74085
dc.description.abstractThe Escherichia coli ribonucleotide reductase (RNR) catalyzes the conversion of nucleoside diphosphates to deoxynucleotides and requires a diferric-tyrosyl radical cofactor for catalysis. RNR is composed of a 1:1 complex of two homodimeric subunits: α and β. Incubation of the E441Q-α mutant RNR with substrate CDP and allosteric effector TTP results in loss of the tyrosyl radical and formation of two new radicals on the 200 ms to min time scale. The first radical was previously established by stopped flow UV/vis spectroscopy and pulsed high field EPR spectroscopy to be a disulfide radical anion. The second radical was proposed to be a 4′-radical of a 3′-keto-2′-deoxycytidine 5′-diphosphate. To identify the structure of the nucleotide radical [1′-[superscript 2]H], [2′-[superscript 2]H], [4′-[superscript 2]H], [5′-[superscript 2]H], [U−[superscript 13]C, [superscript 15]N], [U−[superscript 15]N], and [5,6 -[superscript 2]H] CDP and [β-[superscript 2]H] cysteine-α were synthesized and incubated with E441Q-α2β2 and TTP. The nucleotide radical was examined by 9 GHz and 140 GHz pulsed EPR spectroscopy and 35 GHz ENDOR spectroscopy. Substitution of [superscript 2]H at C4′ and C1′ altered the observed hyperfine interactions of the nucleotide radical and established that the observed structure was not that predicted. DFT calculations (B3LYP/IGLO-III/B3LYP/TZVP) were carried out in an effort to recapitulate the spectroscopic observations and lead to a new structure consistent with all of the experimental data. The results indicate, unexpectedly, that the radical is a semidione nucleotide radical of cytidine 5′-diphosphate. The relationship of this radical to the disulfide radical anion is discussed.en_US
dc.description.sponsorshipNational Institutes of Health (U.S.) (GM29595)en_US
dc.description.sponsorship(EB002804)en_US
dc.description.sponsorship(EB002026)en_US
dc.language.isoen_US
dc.publisherAmerican Chemical Society (ACS)en_US
dc.relation.isversionofhttp://dx.doi.org/10.1021/ja806693sen_US
dc.rightsArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.en_US
dc.sourceACSen_US
dc.titleStructure of the Nucleotide Radical Formed during Reaction of CDP/TTP with the E441Q-α2β2 of E. coli Ribonucleotide Reductaseen_US
dc.typeArticleen_US
dc.identifier.citationZipse, Hendrik et al. “Structure of the Nucleotide Radical Formed During Reaction of CDP/TTP with the E441Q-α2β2 of E. Coli Ribonucleotide Reductase.” Journal of the American Chemical Society 131.1 (2009): 200–211. Copyright © 2008 American Chemical Societyen_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Chemistryen_US
dc.contributor.departmentFrancis Bitter Magnet Laboratory (Massachusetts Institute of Technology)en_US
dc.contributor.mitauthorArtin, Erin
dc.contributor.mitauthorLohman, Gregory J. S.
dc.contributor.mitauthorMartino, Debora
dc.contributor.mitauthorGriffin, Robert Guy
dc.relation.journalJournal of the American Chemical Societyen_US
dc.eprint.versionFinal published versionen_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dspace.orderedauthorsZipse, Hendrik; Artin, Erin; Wnuk, Stanislaw; Lohman, Gregory J. S.; Martino, Debora; Griffin, Robert G.; Kacprzak, Sylwia; Kaupp, Martin; Hoffman, Brian; Bennati, Marina; Stubbe, JoAnne; Lees, Nicholasen
dc.identifier.orcidhttps://orcid.org/0000-0003-1589-832X
mit.licensePUBLISHER_POLICYen_US
mit.metadata.statusComplete


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