2fw0

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Revision as of 08:41, 21 November 2007

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spinqualitylabelsall models 2fw0, resolution 1.55Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Apo Open Form of Glucose/Galactose Binding Protein

Overview

D-Glucose/D-Galactose-binding protein (GGBP) mediates chemotaxis toward, and active transport of glucose and galactose in a number of bacterial, species. GGBP, like other periplasmic binding proteins, can exist in open, (ligand-free) and closed (ligand-bound) states. We report a 0.92 angstroms, resolution structure of GGBP from Escherichia coli in the glucose-bound, state and the first structure of an open, unbound form of GGBP (at 1.55, angstroms resolution). These structures vary in the angle between the two, structural domains; the observed difference of 31 degrees arises from, torsion angle changes in a three-segment hinge. A comparison with the, closely related periplasmic receptors, ribose- and allose-binding, proteins, shows that the GGBP hinge residue positions that undergo the, largest conformational changes are different. Furthermore, the, high-quality data collected for the atomic resolution glucose-bound, structure allow for the refinement of specific hydrogen atom positions, the assignment of alternate side chain conformations, the first, description of CO(2) trapped after radiation-induced decarboxylation, and, insight into the role of the exo-anomeric effect in sugar binding., Together, these structures provide insight into how the hinge-bending, movement of GGBP facilitates ligand binding, transport, and signaling.

About this Structure

2FW0 is a Single protein structure of sequence from Escherichia coli with CA, NA, CIT and MLA as ligands. Full crystallographic information is available from OCA.

Reference

Conformational changes of glucose/galactose-binding protein illuminated by open, unliganded, and ultra-high-resolution ligand-bound structures., Borrok MJ, Kiessling LL, Forest KT, Protein Sci. 2007 Jun;16(6):1032-41. Epub 2007 May 1. PMID:17473016

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