1r53
From Proteopedia
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Crystal structure of the bifunctional chorismate synthase from Saccharomyces cerevisiae
Overview
Chorismate synthase (EC 4.2.3.5), the seventh enzyme in the shikimate, pathway, catalyzes the transformation of 5-enolpyruvylshikimate, 3-phosphate (EPSP) to chorismate, which is the last common precursor in, the biosynthesis of numerous aromatic compounds in bacteria, fungi, and, plants. The chorismate synthase reaction involves a 1,4-trans-elimination, of phosphoric acid from EPSP and has an absolute requirement for reduced, FMN as a cofactor. We have determined the three-dimensional x-ray, structure of the yeast chorismate synthase from selenomethionine-labeled, crystals at 2.2-A resolution. The structure shows a novel, betaalphabetaalpha fold consisting of an alternate tight packing of two, alpha-helical and two beta-sheet layers, showing no resemblance to any, documented protein structure. The molecule is arranged as a tight tetramer, with D2 symmetry, in accordance with its quaternary structure in solution., Electron density is missing for 23% of the amino acids, spread over, sequence regions that in the three-dimensional structure converge on the, surface of the protein. Many totally conserved residues are contained, within these regions, and they probably form a structured but mobile, domain that closes over a cleft upon substrate binding and catalysis. This, hypothesis is supported by previously published spectroscopic measurements, implying that the enzyme undergoes considerable structural changes upon, binding of both FMN and EPSP.
About this Structure
1R53 is a Single protein structure of sequence from Saccharomyces cerevisiae. Active as Chorismate synthase, with EC number 4.2.3.5 Full crystallographic information is available from OCA.
Reference
Crystal structure of the bifunctional chorismate synthase from Saccharomyces cerevisiae., Quevillon-Cheruel S, Leulliot N, Meyer P, Graille M, Bremang M, Blondeau K, Sorel I, Poupon A, Janin J, van Tilbeurgh H, J Biol Chem. 2004 Jan 2;279(1):619-25. Epub 2003 Oct 21. PMID:14573601
Page seeded by OCA on Wed Nov 21 01:16:12 2007
