title: Mechanism of cis-prenyltransferase reaction probed by substrate analogues.
abstract: Undecaprenyl pyrophosphate synthase (UPPS) is a cis-type prenyltransferases which catalyzes condensation reactions of farnesyl diphosphate (FPP) with eight isopentenyl pyrophosphate (IPP) units to generate C(55) product. In this study, we used two analogues of FPP, 2-fluoro-FPP and [1,1-(2)H(2)]FPP, to probe the reaction mechanism of Escherichia coli UPPS. The reaction rate of 2-fluoro-FPP with IPP under single-turnover condition is similar to that of FPP, consistent with the mechanism without forming a farnesyl carbocation intermediate. Moreover, the deuterium secondary KIE of 0.985±0.022 measured for UPPS reaction using [1,1-(2)H(2)]FPP supports the associative transition state. Unlike the sequential mechanism used by trans-prenyltransferases, our data demonstrate E. coli UPPS utilizes the concerted mechanism.
authors.affiliation: Institute of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan, ROC.
authors.forename: Yen-Pin
authors.initials: YP
authors.lastname: Lu
authors.forename: Hon-Ge
authors.initials: HG
authors.lastname: Liu
authors.forename: Kuo-Hsun
authors.initials: KH
authors.lastname: Teng
authors.forename: Po-Huang
authors.initials: PH
authors.lastname: Liang
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000378:metabolism*; D002384:Catalysis; D004926:Escherichia coli / Q000201:enzymology*; D045782:Hemiterpenes / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000378:metabolism*; D011106:Polyisoprenyl Phosphates / Q000378:metabolism*; D012717:Sesquiterpenes / Q000378:metabolism*; D013379:Substrate Specificity; D014166:Transferases / Q000378:metabolism*
chemical_list: C525013:2-fluorofarnesyl diphosphate; D045782:Hemiterpenes; D009943:Organophosphorus Compounds; D011106:Polyisoprenyl Phosphates; D012717:Sesquiterpenes; C004809:isopentenyl pyrophosphate; C004808:farnesyl pyrophosphate; D014166:Transferases; D019883:Alkyl and Aryl Transferases; C106821:cis-prenyl transferase; C023266:undecaprenyl pyrophosphate synthetase