Exploring biosynthetic diversity with trichodiene synthase.
Trichodiene synthase is a terpenoid cyclase that catalyzes the cyclization of farnesyl diphosphate (FPP) to form the bicyclic sesquiterpene hydrocarbon trichodiene (89%), at least five sesquiterpene side products (11%), and inorganic pyrophosphate (PP(i)). Incubation of trichodiene synthase with 2-fluorofarnesyl diphosphate or 4-methylfarnesyl diphosphate similarly yields sesquiterpene mixtures despite the electronic effects or steric bulk introduced by substrate derivatization. The versatility of the enzyme is also demonstrated in the 2.85A resolution X-ray crystal structure of the complex with Mg(2+) (3)-PP(i) and the benzyl triethylammonium cation, which is a bulkier mimic of the bisabolyl carbocation intermediate in catalysis. Taken together, these findings show that the active site of trichodiene synthase is sufficiently flexible to accommodate bulkier and electronically-diverse substrates and intermediates, which could indicate additional potential for the biosynthetic utility of this terpenoid cyclase.
Vedula
L Sangeetha
LS
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
Zhao
Yuxin
Y
Coates
Robert M
RM
Koyama
Tanetoshi
T
Cane
David E
DE
Christianson
David W
DW
D001665:Binding Sites; D019755:Carbon-Carbon Lyases / Q000737:chemistry*; D002413:Cations, Divalent; D018360:Crystallography, X-Ray; D008274:Magnesium / Q000737:chemistry; D008958:Models, Molecular; D010710:Phosphates / Q000737:chemistry; D011106:Polyisoprenyl Phosphates / Q000737:chemistry; D011319:Primaquine / Q000031:analogs & derivatives; D000644:Quaternary Ammonium Compounds / Q000737:chemistry
C525013:2-fluorofarnesyl diphosphate; D002413:Cations, Divalent; D010710:Phosphates; D011106:Polyisoprenyl Phosphates; D000644:Quaternary Ammonium Compounds; C000168:benzyltrimethylammonium; C052061:4-methyl-5-(4-fluorophenoxy)primaquine; D019755:Carbon-Carbon Lyases; C051130:trichodiene synthetase; D008274:Magnesium; D011319:Primaquine