5ik9
From Proteopedia
Tobacco 5-epi-aristolochene with farnesyl monophosphate
Structural highlights
Function5EAS_TOBAC Catalyzes the cyclization of trans,trans-farnesyl diphosphate (FPP) to the bicyclic intermediate 5-epi-aristolochene, initial step in the conversion of FPP to the sesquiterpenoid antifungal phytoalexin capsidiol. Produces germacrene A as an enzyme-bound intermediate that is not released by the enzyme, but is further cyclized to produce the bicyclic 5-epi-aristolochene. Publication Abstract from PubMedThe plant terpene synthase (TPS) family is responsible for the biosynthesis of a variety of terpenoid natural products possessing diverse biological functions. TPSs catalyze the ionization and, most commonly, rearrangement and cyclization of prenyl diphosphate substrates, forming linear and cyclic hydrocarbons. Moreover, a single TPS often produces several minor products in addition to a dominant product. We characterized the catalytic profiles of Hyoscyamus muticus premnaspirodiene synthase (HPS) and compared it with the profile of a closely related TPS, Nicotiana tabacum 5-epi-aristolochene synthase (TEAS). The profiles of two previously studied HPS and TEAS mutants, each containing nine interconverting mutations, dubbed HPS-M9 and TEAS-M9, were also characterized. All four TPSs were compared under varying temperature and pH conditions. In addition, we solved the X-ray crystal structures of TEAS and a TEAS quadruple mutant complexed with substrate and products to gain insight into the enzymatic features modulating product formation. These informative structures, along with product profiles, provide new insight into plant TPS catalytic promiscuity. Biosynthetic potential of sesquiterpene synthases: product profiles of Egyptian Henbane premnaspirodiene synthase and related mutants.,Koo HJ, Vickery CR, Xu Y, Louie GV, O'Maille PE, Bowman M, Nartey CM, Burkart MD, Noel JP J Antibiot (Tokyo). 2016 Jul;69(7):524-33. doi: 10.1038/ja.2016.68. Epub 2016 Jun, 22. PMID:27328867[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Large Structures | Nicotiana tabacum | Bowman M | Koo HJ | Louie GV | Noel JP | Xu Y