4qgy

Camelid (llama) nanobody n25 (VHH) against type 6 secretion system TssM protein

spinqualitylabelsall models 4qgy, resolution 1.38Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4qgy is a 2 chain structure with sequence from Lama glama. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed The type VI secretion system (T6SS) is a secretion pathway widespread in Gram-negative bacteria that targets toxins in both prokaryotic and eukaryotic cells. Although most T6SSs identified so far are involved in inter-bacterial competition, a few are directly required for full virulence of pathogens. The T6SS comprises 13 core proteins that assemble a large complex structurally and functionally similar to a phage contractile tail structure anchored to the cell envelope by a trans-membrane spanning stator. The central part of this stator, TssM, is a 1129-amino-acid protein anchored in the inner membrane that binds to the TssJ outer membrane lipoprotein. In this study, we have raised camelid antibodies against the purified TssM periplasmic domain. We report the crystal structure of two specific nanobodies that bind to TssM in the nanomolar range. Interestingly, the most potent nanobody, nb25, competes with the TssJ lipoprotein for TssM binding in vitro suggesting that TssJ and the nb25 CDR3 loop share the same TssM binding site or causes a steric hindrance preventing TssM-TssJ complex formation. Indeed, periplasmic production of the nanobodies displacing the TssM-TssJ interaction inhibits the T6SS function in vivo. This study illustrates the power of nanobodies to specifically target and inhibit bacterial secretion systems. Inhibition of Type VI Secretion by an Anti-TssM Llama Nanobody.,Nguyen VS, Logger L, Spinelli S, Desmyter A, Le TT, Kellenberger C, Douzi B, Durand E, Roussel A, Cascales E, Cambillau C PLoS One. 2015 Mar 26;10(3):e0122187. doi: 10.1371/journal.pone.0122187., eCollection 2015. PMID:25811612 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Antibody 3D structures 3D structures of non-human antibody

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