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dc.contributor.authorGräwert, Tobias
dc.contributor.authorSpan, Ingrid
dc.contributor.authorEisenreich, Wolfgang
dc.contributor.authorRohdich, Felix
dc.contributor.authorEppinger, Jörg
dc.contributor.authorBacher, Adelbert
dc.contributor.authorGroll, Michael
dc.date.accessioned2015-08-02T09:11:30Z
dc.date.available2015-08-02T09:11:30Z
dc.date.issued2009-12-28
dc.identifier.citationGrawert, T., Span, I., Eisenreich, W., Rohdich, F., Eppinger, J., Bacher, A., & Groll, M. (2009). Probing the reaction mechanism of IspH protein by x-ray structure analysis. Proceedings of the National Academy of Sciences, 107(3), 1077–1081. doi:10.1073/pnas.0913045107
dc.identifier.issn00278424
dc.identifier.pmid20080550
dc.identifier.doi10.1073/pnas.0913045107
dc.identifier.urihttp://hdl.handle.net/10754/561445
dc.description.abstractIsopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) represent the two central intermediates in the biosynthesis of isoprenoids. The recently discovereddeoxyxylulose 5-phosphate pathway generates a mixture of IPP and DMAPP in its final step by reductive dehydroxylation of 1-hydroxy-2-methyl- 2-butenyl 4-diphosphate. This conversion is catalyzed by IspH protein comprising a central iron-sulfur cluster as electron transfer cofactor in the active site. The five crystal structures of IspH in complex with substrate, converted substrate, products and PPi reported in this article provide unique insights into the mechanism of this enzyme. While IspH protein crystallizes with substrate bound to a [4Fe-4S] cluster, crystals of IspH in complex with IPP, DMAPP or inorganic pyrophosphate feature [3Fe-4S] clusters. The IspH:substrate complex reveals a hairpin conformation of the ligand with the C(1) hydroxyl group coordinated to the unique site in a [4Fe-4S] cluster of aconitase type. The resulting alkoxide complex is coupled to a hydrogen-bonding network, which serves as proton reservoir via a Thr167 proton relay. Prolonged x-ray irradiation leads to cleavage of the C(1)-O bond (initiated by reducing photo electrons). The data suggest a reaction mechanism involving a combination of Lewis-acid activation and proton coupled electron transfer. The resulting allyl radical intermediate can acquire a second electron via the iron-sulfur cluster. The reaction may be terminated by the transfer of a proton from the β-phosphate of the substrate to C(1) (affording DMAPP) or C(3) (affording IPP).
dc.publisherProceedings of the National Academy of Sciences
dc.relation.urlhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2824267
dc.subjectIron-sulfur protein
dc.subjectIsoprenoid biosynthesis
dc.subjectLytB protein
dc.subjectNonmevalonate pathway
dc.subjectTerpene biosynthesis
dc.titleProbing the reaction mechanism of IspH protein by x-ray structure analysis
dc.typeArticle
dc.contributor.departmentBiological & Organometallic Catalysis Laboratories
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Division
dc.contributor.departmentChemical Science Program
dc.contributor.departmentKAUST Catalysis Center (KCC)
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.identifier.journalProceedings of the National Academy of Sciences
dc.identifier.pmcidPMC2824267
dc.contributor.institutionCenter for Integrated Protein Science, Department Chemie, Lehrstuhl für Biochemie, Technische Universität München, Lichtenbergstrasse 4, Garching, Germany
dc.contributor.institutionMerck KGaA, Frankfurter Strasse 250, 64293 Darmstadt, Germany
kaust.personEppinger, Jorg
dc.date.published-online2009-12-28
dc.date.published-print2010-01-19


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