3zcj

Crystal structure of Helicobacter pylori T4SS protein CagL in a tetragonal crystal form with a helical RGD-motif (6 Mol per ASU)

spinqualitylabelsall models 3zcj, resolution 3.25Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3zcj is a 6 chain structure with sequence from Helicobacter pylori 26695. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.25Å Ligands: GOL, K, MLY, PEG, PO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function O25272_HELPY Publication Abstract from PubMed RGD tripeptide motifs frequently mediate ligand binding to integrins. The type IV secretion system (T4SS) protein CagL of the gastric pathogen Helicobacter pylori also contains an RGD motif. CagL decorates the T4SS pilus and may function as an adhesin for host cells. Whether CagL binds integrins via its RGD motif is under debate. Here, we present crystal structures of CagL revealing an elongated four-helix bundle that appears evolutionarily unrelated to the proposed VirB5 orthologs. The RGD motif is surface-exposed but located within a long alpha helix. This is unprecedented as previously characterized integrin-binding RGD motifs are located within extended or flexible loops. Yet, adhesion of gastric epithelial cells to CagL was strictly RGD-dependent. Comparison of seven crystallographically independent molecules reveals substantial structural flexibility. Intramolecular disulfide bonds engineered to reduce CagL flexibility resulted in more stable protein, but unable to support cell adhesion. CagL may thus partly unfold during receptor binding. A Helical RGD Motif Promoting Cell Adhesion: Crystal Structures of the Helicobacter pylori Type IV Secretion System Pilus Protein CagL.,Barden S, Lange S, Tegtmeyer N, Conradi J, Sewald N, Backert S, Niemann HH Structure. 2013 Sep 25. pii: S0969-2126(13)00310-9. doi:, 10.1016/j.str.2013.08.018. PMID:24076404 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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