3lg5 | pdb_00003lg5

F198A Epi-isozizaene synthase: Complex with Mg, inorganic pyrophosphate and benzyl triethyl ammonium cation

spinqualitylabelsall models 3lg5, resolution 1.64Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3lg5 is a 1 chain structure with sequence from "actinomyces_coelicolor"_(muller_1908)_lieske_1921 "actinomyces coelicolor" (muller 1908) lieske 1921. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: BTM, MG, POP, SO4 Related: 3kb9, 3kbk, 3lgk Gene: cyc1, SCO5222, SC7E4.19 ("Actinomyces coelicolor" (Muller 1908) Lieske 1921) Activity: Epi-isozizaene synthase, with EC number 4.2.3.37 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [CYC1_STRCO] Catalyzes the cyclization of farnesyl diphosphate (FPP) to the sesquiterpene epi-isozizaene. 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 The X-ray crystal structure of recombinant epi-isozizaene synthase (EIZS), a sesquiterpene cyclase from Streptomyces coelicolor A3(2), has been determined at 1.60 A resolution. Specifically, the structure of wild-type EIZS is that of its closed conformation in complex with three Mg(2+) ions, inorganic pyrophosphate (PP(i)), and the benzyltriethylammonium cation (BTAC). Additionally, the structure of D99N EIZS has been determined in an open, ligand-free conformation at 1.90 A resolution. Comparison of these two structures provides the first view of conformational changes required for substrate binding and catalysis in a bacterial terpenoid cyclase. Moreover, the binding interactions of BTAC may mimic those of a carbocation intermediate in catalysis. Accordingly, the aromatic rings of F95, F96, and F198 appear to be well-oriented to stabilize carbocation intermediates in the cyclization cascade through cation-pi interactions. Mutagenesis of aromatic residues in the enzyme active site results in the production of alternative sesquiterpene product arrays due to altered modes of stabilization of carbocation intermediates as well as altered templates for the cyclization of farnesyl diphosphate. Accordingly, the 1.64 A resolution crystal structure of F198A EIZS in a complex with three Mg(2+) ions, PP(i), and BTAC reveals an alternative binding orientation of BTAC; alternative binding orientations of a carbocation intermediate could lead to the formation of alternative products. Finally, the crystal structure of wild-type EIZS in a complex with four Hg(2+) ions has been determined at 1.90 A resolution, showing that metal binding triggers a significant conformational change of helix G to cap the active site. Structure of epi-isozizaene synthase from Streptomyces coelicolor A3(2), a platform for new terpenoid cyclization templates.,Aaron JA, Lin X, Cane DE, Christianson DW Biochemistry. 2010 Mar 2;49(8):1787-97. PMID:20131801 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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