5whv

Crystal structure of ArtB

spinqualitylabelsall models 5whv, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5whv is a 10 chain structure with sequence from Salmonella enterica subsp. enterica serovar Typhimurium str. DT104. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.303Å Ligands: CA, CL, MES, PEG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q404H3_SALTM Publication Abstract from PubMed The evolution of virulence traits is central for the emergence or re-emergence of microbial pathogens and for their adaptation to a specific host 1-5 . Typhoid toxin is an essential virulence factor of the human-adapted bacterial pathogen Salmonella Typhi 6,7 , the cause of typhoid fever in humans 8-12 . Typhoid toxin has a unique A2B5 architecture with two covalently linked enzymatic 'A' subunits, PltA and CdtB, associated with a homopentameric 'B' subunit made up of PltB, which has binding specificity for the N-acetylneuraminic acid (Neu5Ac) sialoglycans 6,13 predominantly present in humans 14 . Here, we examine the functional and structural relationship between typhoid toxin and ArtAB, an evolutionarily related AB5 toxin encoded by the broad-host Salmonella Typhimurium 15 . We find that ArtA and ArtB, homologues of PltA and PltB, can form a functional complex with the typhoid toxin CdtB subunit after substitution of a single amino acid in ArtA, while ArtB can form a functional complex with wild-type PltA and CdtB. We also found that, after addition of a single-terminal Cys residue, a CdtB homologue from cytolethal distending toxin can form a functional complex with ArtA and ArtB. In line with the broad host specificity of S. Typhimurium, we found that ArtB binds human glycans, terminated in N-acetylneuraminic acid, as well as glycans terminated in N-glycolylneuraminic acid (Neu5Gc), which are expressed in most other mammals 14 . The atomic structure of ArtB bound to its receptor shows the presence of an additional glycan-binding site, which broadens its binding specificity. Despite equivalent toxicity in vitro, we found that the ArtB/PltA/CdtB chimaeric toxin exhibits reduced lethality in an animal model, indicating that the host specialization of typhoid toxin has optimized its targeting mechanisms to the human host. This is a remarkable example of a toxin evolving to broaden its enzymatic activities and adapt to a specific host.Structural illumination of host glycan interaction in the evolution and host adaptation of the Salmonella typhoid toxin. Evolution of host adaptation in the Salmonella typhoid toxin.,Gao X, Deng L, Stack G, Yu H, Chen X, Naito-Matsui Y, Varki A, Galan JE Nat Microbiol. 2017 Oct 9. doi: 10.1038/s41564-017-0033-2. PMID:28993610 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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