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.
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
L Sangeetha
LS
Vedula
Yuxin
Y
Zhao
Robert M
RM
Coates
Tanetoshi
T
Koyama
David E
DE
Cane
David W
DW
Christianson
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