1u0v
From Proteopedia
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An Aldol Switch Discovered in Stilbene Synthases Mediates Cyclization of Specificity of Type III Polyketide Synthases: 18xCHS structure
Overview
Stilbene synthase (STS) and chalcone synthase (CHS) each catalyze the, formation of a tetraketide intermediate from a CoA-tethered, phenylpropanoid starter and three molecules of malonyl-CoA, but use, different cyclization mechanisms to produce distinct chemical scaffolds, for a variety of plant natural products. Here we present the first STS, crystal structure and identify, by mutagenic conversion of alfalfa CHS, into a functional stilbene synthase, the structural basis for the, evolution of STS cyclization specificity in type III polyketide synthase, (PKS) enzymes. Additional mutagenesis and enzymatic characterization, confirms that electronic effects rather than steric factors balance, competing cyclization specificities in CHS and STS. Finally, we discuss, the problematic in vitro reconstitution of plant stilbenecarboxylate, pathways, using insights from existing biomimetic polyketide cyclization, studies to generate a novel mechanistic hypothesis to explain, stilbenecarboxylate biosynthesis.
About this Structure
1U0V is a Single protein structure of sequence from Medicago sativa. Active as Naringenin-chalcone synthase, with EC number 2.3.1.74 Full crystallographic information is available from OCA.
Reference
An aldol switch discovered in stilbene synthases mediates cyclization specificity of type III polyketide synthases., Austin MB, Bowman ME, Ferrer JL, Schroder J, Noel JP, Chem Biol. 2004 Sep;11(9):1179-94. PMID:15380179
Page seeded by OCA on Wed Nov 21 03:45:31 2007
Categories: Medicago sativa | Naringenin-chalcone synthase | Single protein | Austin, M.B. | Bowman, M.E. | Ferrer, J.L. | Noel, J.P. | Schroder, J. | Aldol switch | Alpha-beta-alpha-beta-alpha fold | Catalytic triad | Condensing enzyme | Engineered resveratrol synthase | Pks | Thiolase fold | Type iii polyketide synthase
