3i5o

The X-ray crystal structure of a thermophilic cellobiose binding protein bound with cellopentaose

spinqualitylabelsall models 3i5o, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3i5o is a 2 chain structure with sequence from Thermotoga maritima. This structure supersedes the now removed PDB entry 2o7j. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.5Å Ligands: BGC, PRD_900016 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q9WXN8_THEMA Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Periplasmic binding proteins (PBPs) constitute a protein superfamily that binds a wide variety of ligands. In prokaryotes, PBPs function as receptors for ATP-binding cassette or tripartite ATP-independent transporters and chemotaxis systems. In many instances, PBPs bind their cognate ligands with exquisite specificity, distinguishing, for example, between sugar epimers or structurally similar anions. By contrast, oligopeptide-binding proteins bind their ligands through interactions with the peptide backbone but do not distinguish between different side chains. The extremophile Thermotoga maritima possesses a remarkable array of carbohydrate-processing metabolic systems, including the hydrolysis of cellulosic polymers. Here, we present the crystal structure of a T. maritima cellobiose-binding protein (tm0031) that is homologous to oligopeptide-binding proteins. T. maritima cellobiose-binding protein binds a variety of lengths of beta(1-->4)-linked glucose oligomers, ranging from two rings (cellobiose) to five (cellopentaose). The structure reveals that binding is semi-specific. The disaccharide at the nonreducing end binds specifically; the other rings are located in a large solvent-filled groove, where the reducing end makes several contacts with the protein, thereby imposing an upper limit of the oligosaccharides that are recognized. Semi-specific recognition, in which a molecular class rather than individual species is selected, provides an efficient solution for the uptake of complex mixtures. Structural analysis of semi-specific oligosaccharide recognition by a cellulose-binding protein of thermotoga maritima reveals adaptations for functional diversification of the oligopeptide periplasmic binding protein fold.,Cuneo MJ, Beese LS, Hellinga HW J Biol Chem. 2009 Nov 27;284(48):33217-23. Epub 2009 Oct 2. PMID:19801540 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also ABC transporter 3D structures

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