3bnx
From Proteopedia
Crystal structure of Aristolochene synthase complexed with farnesyl diphosphate
Overview
The universal sesquiterpene precursor, farnesyl diphosphate (FPP), is cyclized in an Mg(2+)-dependent reaction catalyzed by the tetrameric aristolochene synthase from Aspergillus terreus to form the bicyclic hydrocarbon aristolochene and a pyrophosphate anion (PP(i)) coproduct. The 2.1-A resolution crystal structure determined from crystals soaked with FPP reveals the binding of intact FPP to monomers A-C, and the binding of PP(i) and Mg(2+)(B) to monomer D. The 1.89-A resolution structure of the complex with 2-fluorofarnesyl diphosphate (2F-FPP) reveals 2F-FPP binding to all subunits of the tetramer, with Mg(2+)(B)accompanying the binding of this analogue only in monomer D. All monomers adopt open activesite conformations in these complexes, but slight structural changes in monomers C and D of each complex reflect the very initial stages of a conformational transition to the closed state. Finally, the 2.4-A resolution structure of the complex with 12,13-difluorofarnesyl diphosphate (DF-FPP) reveals the binding of intact DF-FPP to monomers A-C in the open conformation and the binding of PP(i), Mg(2+)(B), and Mg(2+)(C) to monomer D in a predominantly closed conformation. Taken together, these structures provide 12 independent "snapshots" of substrate or product complexes that suggest a possible sequence for metal ion binding and conformational changes required for catalysis.
About this Structure
3BNX is a Single protein structure of sequence from Aspergillus terreus. Full crystallographic information is available from OCA.
Reference
X-ray Crystallographic Studies of Substrate Binding to Aristolochene Synthase Suggest a Metal Ion Binding Sequence for Catalysis., Shishova EY, Yu F, Miller DJ, Faraldos JA, Zhao Y, Coates RM, Allemann RK, Cane DE, Christianson DW, J Biol Chem. 2008 May 30;283(22):15431-9. Epub 2008 Apr 2. PMID:18385128 Page seeded by OCA on Wed Jun 11 10:57:12 2008
