2ps8
From Proteopedia
Y295F Trichodiene Synthase: Complex With Mg and Pyrophosphate
Structural highlights
FunctionTRI5_FUSSP TS is a member of the terpene cyclase group of enzymes. It catalyzes the isomerization and cyclization of farnesyl pyro-phosphate to form trichodiene, the first cyclic intermediate in the biosynthetic pathway for trichothecenes. It serves to branch trichothecene biosynthesis from the isoprenoid pathway. 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 PubMedTrichodiene synthase from Fusarium sporotrichioides contains two metal ion-binding motifs required for the cyclization of farnesyl diphosphate: the "aspartate-rich" motif D(100)DXX(D/E) that coordinates to Mg2+A and Mg2+C, and the "NSE/DTE" motif N(225)DXXSXXXE that chelates Mg2+B (boldface indicates metal ion ligands). Here, we report steady-state kinetic parameters, product array analyses, and X-ray crystal structures of trichodiene synthase mutants in which the fungal NSE motif is progressively converted into a plant-like DDXXTXXXE motif, resulting in a degradation in both steady-state kinetic parameters and product specificity. Each catalytically active mutant generates a different distribution of sesquiterpene products, and three newly detected sesquiterpenes are identified. In addition, the kinetic and structural properties of the Y295F mutant of trichodiene synthase were found to be similar to those of the wild-type enzyme, thereby ruling out a proposed role for Y295 in catalysis. Structural and mechanistic analysis of trichodiene synthase using site-directed mutagenesis: probing the catalytic function of tyrosine-295 and the asparagine-225/serine-229/glutamate-233-Mg2+B motif.,Vedula LS, Jiang J, Zakharian T, Cane DE, Christianson DW Arch Biochem Biophys. 2008 Jan 15;469(2):184-94. Epub 2007 Oct 30. PMID:17996718[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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