1x09

Crystal structure of the D26A mutant UPPs in complex with magnesium and isopentenyl pyrophosphate

spinqualitylabelsall models 1x09, resolution 1.87Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1x09 is a 1 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: IPE, MG Related: 1jp3, 1v7u, 1ueh, 1x06, 1x07, 1x08 Activity: Ditrans,polycis-undecaprenyl-diphosphate synthase ((2E,6E)-farnesyl- diphosphate specific), with EC number 2.5.1.31 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [UPPS_ECOLI] Generates ditrans,octacis-undecaprenyl pyrophosphate (UPP) from isopentenyl pyrophosphate (IPP) and farnesyl diphosphate (FPP). UPP is the precursor of glycosyl carrier lipid in the biosynthesis of bacterial cell wall polysaccharide components such as peptidoglycan and lipopolysaccharide. 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 PubMed Undecaprenyl pyrophosphate synthase (UPPs) catalyzes the consecutive condensation reactions of a farnesyl pyrophosphate (FPP) with eight isopentenyl pyrophosphates (IPP), in which new cis-double bonds are formed, to generate undecaprenyl pyrophosphate that serves as a lipid carrier for peptidoglycan synthesis of bacterial cell wall. The structures of Escherichia coli UPPs were determined previously in an orthorhombic crystal form as an apoenzyme, in complex with Mg(2+)/sulfate/Triton, and with bound FPP. In a further search of its catalytic mechanism, the wild-type UPPs and the D26A mutant are crystallized in a new trigonal unit cell with Mg(2+)/IPP/farnesyl thiopyrophosphate (an FPP analogue) bound to the active site. In the wild-type enzyme, Mg(2+) is coordinated by the pyrophosphate of farnesyl thiopyrophosphate, the carboxylate of Asp(26), and three water molecules. In the mutant enzyme, it is bound to the pyrophosphate of IPP. The [Mg(2+)] dependence of the catalytic rate by UPPs shows that the activity is maximal at [Mg(2+)] = 1 mm but drops significantly when Mg(2+) ions are in excess (50 mm). Without Mg(2+), IPP binds to UPPs only at high concentration. Mutation of Asp(26) to other charged amino acids results in significant decrease of the UPPs activity. The role of Asp(26) is probably to assist the migration of Mg(2+) from IPP to FPP and thus initiate the condensation reaction by ionization of the pyrophosphate group from FPP. Other conserved residues, including His(43), Ser(71), Asn(74), and Arg(77), may serve as general acid/base and pyrophosphate carrier. Our results here improve the understanding of the UPPs enzyme reaction significantly. Crystal structures of undecaprenyl pyrophosphate synthase in complex with magnesium, isopentenyl pyrophosphate, and farnesyl thiopyrophosphate: roles of the metal ion and conserved residues in catalysis.,Guo RT, Ko TP, Chen AP, Kuo CJ, Wang AH, Liang PH J Biol Chem. 2005 May 27;280(21):20762-74. Epub 2005 Mar 23. PMID:15788389 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Undecaprenyl pyrophosphate synthase

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