1com
From Proteopedia
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THE MONOFUNCTIONAL CHORISMATE MUTASE FROM BACILLUS SUBTILIS: STRUCTURE DETERMINATION OF CHORISMATE MUTASE AND ITS COMPLEXES WITH A TRANSITION STATE ANALOG AND PREPHENATE, AND IMPLICATIONS ON THE MECHANISM OF ENZYMATIC REACTION
Overview
Structures have been determined for chorismate mutase from Bacillus, subtilis and of complexes of this enzyme with product and an, endo-oxabicyclic transition state analog using multiple isomorphous, replacement plus partial structure phase combination and, non-crystallographic averaging. In addition to 522 water molecules, the, model includes 1380 of the 1524 amino acid residues of the four trimers, (each containing 3 x 127 amino acid residues) in the asymmetric unit., Refinement to 1.9 A resolution yields 0.194 for R and r.m.s. deviations, from ideal values of 0.014 A for bond lengths and 2.92 degrees for bond, angles. The trimer resembles a beta-barrel structure in which a core, beta-sheet is surrounded by helices. The structures of the two complexes, locate the active sites which are at the interfaces of adjacent pairs of, monomers in the trimer. These structures have been refined at 2.2 A to a, crystallographic R value of 0.18 and show r.m.s. deviations from ideal, values of 0.013 A for bond lengths and 2.84 degrees or 3.05 degrees for, bond angles, respectively. The final models have 1398 amino acid residues, nine prephenate molecules and 503 water molecules in the product complex, and 1403 amino acid residues, 12 inhibitor molecules and 530 water, molecules in the transition state complex. The active sites of all three, of these structures are very similar and provide a structural basis for, the biochemical studies that indicate a pericyclic mechanism for, conversion of chorismate to prephenate. The absence of reactive catalytic, residues on the enzyme, the selective binding of the single reactive, conformation of chorismate, the stabilization of the polar transition, state, and the possible role of the C-terminal region in "capping" the, active site are factors which relate these structures to the million-fold, rate enhancement of this reaction.
About this Structure
1COM is a Single protein structure of sequence from Bacillus subtilis with PRE as ligand. Active as Chorismate mutase, with EC number 5.4.99.5 Full crystallographic information is available from OCA.
Reference
The monofunctional chorismate mutase from Bacillus subtilis. Structure determination of chorismate mutase and its complexes with a transition state analog and prephenate, and implications for the mechanism of the enzymatic reaction., Chook YM, Gray JV, Ke H, Lipscomb WN, J Mol Biol. 1994 Jul 29;240(5):476-500. PMID:8046752
Page seeded by OCA on Tue Nov 20 12:37:44 2007
