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1ggg
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(New page: 200px<br /><applet load="1ggg" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ggg, resolution 2.3Å" /> '''GLUTAMINE BINDING PRO...)
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Revision as of 13:54, 20 November 2007
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GLUTAMINE BINDING PROTEIN OPEN LIGAND-FREE STRUCTURE
Overview
The crystal structure of the glutamine-binding protein (GlnBP) from, Escherichia coli in a ligand-free "open" conformational state has been, determined by isomorphous replacement methods and refined to an R-value of, 21.4% at 2.3 A resolution. There are two molecules in the asymmetric unit, related by pseudo 4-fold screw symmetry. The refined model consists of, 3587 non-hydrogen atoms from 440 residues (two monomers), and 159 water, molecules. The structure has root-mean-square deviations of 0.013 A from, "ideal" bond lengths and 1.5 degrees from "ideal" bond angles. The GlnBP, molecule has overall dimensions of approximately 60 A x 40 A x 35 A and is, made up of two domains (termed large and small), which exhibit a similar, supersecondary structure, linked by two antiparallel beta-strands. The, small domain contains three alpha-helices and four parallel and one, antiparallel beta-strands. The large domain is similar to the small domain, but contains two additional alpha-helices and three more short, antiparallel beta-strands. A comparison of the secondary structural motifs, of GlnBP with those of other periplasmic binding proteins is discussed. A, model of the "closed form" GlnBP-Gln complex has been proposed based on, the crystal structures of the histidine-binding protein-His complex and, "open form" GlnBP. This model has been successfully used as a search model, in the crystal structure determination of the "closed form" GlnBP-Gln, complex by molecular replacement methods. The model agrees remarkably well, with the crystal structure of the Gln-GlnBP complex with root-mean-square, deviation of 1.29 A. Our study shows that, at least in our case, it is, possible to predict one conformational state of a periplasmic binding, protein from another conformational state of the protein. The, glutamine-binding pockets of the model and the crystal structure are, compared and the modeling technique is described.
About this Structure
1GGG is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
The crystal structure of glutamine-binding protein from Escherichia coli., Hsiao CD, Sun YJ, Rose J, Wang BC, J Mol Biol. 1996 Sep 20;262(2):225-42. PMID:8831790
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