1eps
From Proteopedia
|
STRUCTURE AND TOPOLOGICAL SYMMETRY OF THE GLYPHOSPHATE 5-ENOL-PYRUVYLSHIKIMATE-3-PHOSPHATE SYNTHASE: A DISTINCTIVE PROTEIN FOLD
Overview
5-enol-Pyruvylshikimate-3-phosphate synthase (EPSP synthase;, phosphoenolpyruvate:3-phosphoshikimate 1-carboxyvinyltransferase, EC, 2.5.1.19) is an enzyme on the pathway toward the synthesis of aromatic, amino acids in plants, fungi, and bacteria and is the target of the, broad-spectrum herbicide glyphosate. The three-dimensional structure of, the enzyme from Escherichia coli has been determined by crystallographic, techniques. The polypeptide backbone chain was traced by examination of an, electron density map calculated at 3-A resolution. The two-domain, structure has a distinctive fold and appears to be formed by 6-fold, replication of a protein folding unit comprising two parallel helices and, a four-stranded sheet. Each domain is formed from three of these units, which are related by an approximate threefold symmetry axis; in each, domain three of the helices are completely buried by a surface formed from, the three beta-sheets and solvent-accessible faces of the other three, helices. The domains are related by an approximate dyad, but in the, present crystals the molecule does not display pseudo-symmetry related to, the symmetry of point group 32 because its approximate threefold axes are, almost normal. A possible relation between the three-dimensional structure, of the protein and the linear sequence of its gene will be described. The, topological threefold symmetry and orientation of each of the two observed, globular domains may direct the binding of substrates and inhibitors by a, helix macrodipole effect and implies that the active site is located near, the interdomain crossover segments. The structure also suggests a, rationale for the glyphosate tolerance conferred by sequence alterations.
About this Structure
1EPS is a Single protein structure of sequence from Escherichia coli. Active as Riboflavin synthase, with EC number 2.5.1.9 Full crystallographic information is available from OCA.
Reference
Structure and topological symmetry of the glyphosate target 5-enolpyruvylshikimate-3-phosphate synthase: a distinctive protein fold., Stallings WC, Abdel-Meguid SS, Lim LW, Shieh HS, Dayringer HE, Leimgruber NK, Stegeman RA, Anderson KS, Sikorski JA, Padgette SR, Kishore GM, Proc Natl Acad Sci U S A. 1991 Jun 1;88(11):5046-50. PMID:11607190
Page seeded by OCA on Tue Nov 20 14:12:49 2007
