8SU5
F198T epi-Isozizaene Synthase: complex with 3 Mg2+, inorganic pyrophosphate, and benzyl triethyl ammonium cation
Summary for 8SU5
| Entry DOI | 10.2210/pdb8su5/pdb |
| Descriptor | Epi-isozizaene synthase, N-benzyl-N,N-diethylethanaminium, SULFATE ION, ... (7 entities in total) |
| Functional Keywords | terpene, terpenoid, isoprenoid, terpene cyclase, terpene synthase, lyase |
| Biological source | Streptomyces coelicolor A3(2) |
| Total number of polymer chains | 1 |
| Total formula weight | 44299.29 |
| Authors | Eaton, S.A.,Christianson, D.W. (deposition date: 2023-05-11, release date: 2023-07-26, Last modification date: 2023-08-16) |
| Primary citation | Eaton, S.A.,Christianson, D.W. Reprogramming the Cyclization Cascade of epi -Isozizaene Synthase to Generate Alternative Terpene Products. Biochemistry, 62:2301-2313, 2023 Cited by PubMed Abstract: The class I sesquiterpene cyclase -isozizaene synthase from (EIZS) catalyzes the transformation of linear farnesyl diphosphate (FPP) into the tricyclic hydrocarbon -isozizaene in the biosynthesis of albaflavenone antibiotics. The active site cavity of EIZS is largely framed by four aromatic residues - F95, F96, F198, and W203 - that form a product-shaped contour, serving as a template to chaperone conformations of the flexible substrate and multiple carbocation intermediates leading to -isozizaene. Remolding the active site contour by mutagenesis can redirect the cyclization cascade away from -isozizaene biosynthesis to generate alternative sesquiterpene products. Here, we present the biochemical and structural characterization of four EIZS mutants in which aromatic residues have been substituted with polar residues (F95S, F96H, F198S, and F198T) to generate alternative cyclization products. Most notably, F95S EIZS generates a mixture of monocyclic sesquiterpene precursors of bisabolane, a D2 diesel fuel substitute. X-ray crystal structures of the characterized mutants reveal subtle changes in the active site contour showing how each aromatic residue influences the chemistry of a different carbocation intermediate in the cyclization cascade. We advance that EIZS may serve as a robust platform for the development of designer cyclases for the generation of high-value sesquiterpene products ranging from pharmaceuticals to biofuels in synthetic biology approaches. PubMed: 37449555DOI: 10.1021/acs.biochem.3c00247 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.48 Å) |
Structure validation
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