7c64

Crystal structure of beta-glycosides-binding protein of ABC transporter in an open state (Form II)

spinqualitylabelsall models 7c64, resolution 1.63Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7c64 is a 2 chain structure with sequence from Thermus thermophilus HB8. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.63Å Ligands: CL, CO2, EDO, MRY, P33, PEG, PG4, PGE, PO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q53W80_THET8 Publication Abstract from PubMed Substrate-binding proteins (SBPs), selectively capture ligand(s) and ensure their translocation via its cognate ATP-binding cassette (ABC) import system. SBPs bind their cognate ligand(s) via an induced-fit mechanism known as the "Venus Fly-trap"; however, this mechanism lacks the atomic details of all conformational landscape as the confirmatory evidence(s) in its support. In this study, we delineate the atomic details of an SBP, beta-glucosides-binding protein (betaGlyBP) from Thermus thermophilus HB8. The protein betaGlyBP is multi-specific and binds to different types of beta-glucosides varying in their glycosidic linkages viz. beta-1,2; beta-1,3; beta-1,4 and beta-1,6 with a degree of polymerization of 2-5 glucosyl units. Structurally, the protein betaGlyBP possesses four subdomains (N1, N2, C1 and C2). The unliganded protein betaGlyBP remains in an open state, which closes upon binding to sophorose (SOP2), laminari-oligosaccharides (LAMn), cello-oligosaccharides (CELn), and gentiobiose (GEN2). This study reports, for the first time, four different structural states (open-unliganded, partial-open-unliganded, open-liganded and closed-liganded) of the protein betaGlyBP, revealing its conformational changes upon ligand binding and suggesting a two-step induced-fit mechanism. Further, results suggest that the conformational changes of N1 and C1 subdomains drive the ligand binding, unlike that of the whole N- and C-terminal domains (NTD and CTD) as known in the "Venus Fly-trap" mechanism. Additionally, profiling of stereo-selection mechanism for alpha- and beta-glucosides reveals that in the ligand-binding site four secondary structural elements (L1, H1, H2 and H3) drive the ligand selection. In summary, results demonstrate that the details of conformational changes and ligand selection are pre-encoded in the SBPs. Conformational Trapping of a beta-Glucosides-Binding Protein Unveils the Selective Two-Step Ligand-Binding Mechanism of ABC Importers.,Chandravanshi M, Samanta R, Kanaujia SP J Mol Biol. 2020 Aug 28. pii: S0022-2836(20)30515-5. doi:, 10.1016/j.jmb.2020.08.021. PMID:32866452 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also ABC transporter 3D structures

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