Files in this item
Periplasmic depolymerase provides insight into ABC transporter-dependent secretion of bacterial capsular polysaccharides
Item metadata
dc.contributor.author | Liston, Sean D. | |
dc.contributor.author | McMahon, Stephen A. | |
dc.contributor.author | Le Bas, Audrey | |
dc.contributor.author | Suits, Michael D. L. | |
dc.contributor.author | Naismith, James H. | |
dc.contributor.author | Whitfield, Chris | |
dc.date.accessioned | 2018-06-06T14:30:05Z | |
dc.date.available | 2018-06-06T14:30:05Z | |
dc.date.issued | 2018-05-22 | |
dc.identifier | 253291301 | |
dc.identifier | 99f7fc15-973c-481a-90a9-e95dae36f4b5 | |
dc.identifier | 000432663000019 | |
dc.identifier | 29735649 | |
dc.identifier | 85047350859 | |
dc.identifier | 000432663000019 | |
dc.identifier.citation | Liston , S D , McMahon , S A , Le Bas , A , Suits , M D L , Naismith , J H & Whitfield , C 2018 , ' Periplasmic depolymerase provides insight into ABC transporter-dependent secretion of bacterial capsular polysaccharides ' , Proceedings of the National Academy of Sciences of the United States of America , vol. 115 , no. 21 , pp. E4870-E4879 . https://doi.org/10.1073/pnas.1801336115 | en |
dc.identifier.issn | 0027-8424 | |
dc.identifier.uri | https://hdl.handle.net/10023/13781 | |
dc.description | This work was supported in part by grants from the Canadian Institutes of Health Research (FDN_148364) (to C.W.). S.D.L. is a recipient of a Natural Science and Engineering Research Council Alexander Graham Bell Canada Graduate Scholarship and Michael Smith Foreign Study Supplement. C.W. is a Canada Research Chair. J.H.N. is a Wellcome Trust Investigator (100209/Z/12/Z). | en |
dc.description.abstract | Capsules are surface layers of hydrated capsular polysaccharides (CPSs) produced by many bacteria. The human pathogen Salmonella enterica serovar Typhi produces "Vi antigen" CPS, which contributes to virulence. In a conserved strategy used by bacteria with diverse CPS structures, translocation of Vi antigen to the cell surface is driven by an ATP-binding cassette (ABC) transporter. These transporters are engaged in heterooligomeric complexes proposed to form an enclosed translocation conduit to the cell surface, allowing the transporter to power the entire process. We identified Vi antigen biosynthesis genetic loci in genera of the Burkholderiales, which are paradoxically distinguished from S. Typhi by encoding VexL, a predicted pectate lyase homolog. Biochemical analyses demonstrated that VexL is an unusual metal-independent endolyase with an acidic pH optimum that is specific for Oacetylated Vi antigen. A 1.22-Å crystal structure of the VexL-Vi antigen complex revealed features which distinguish common secreted catabolic pectate lyases from periplasmic VexL, which participates in cell-surface assembly. VexL possesses a right-handed parallel beta-superhelix, of which one face forms an electropositive glycan-binding groove with an extensive hydrogen bonding network that includes Vi antigen acetyl groups and confers substrate specificity. VexL provided a probe to interrogate conserved features of the ABC transporter-dependent export model. When introduced into S. Typhi, VexL localized to the periplasm and degraded Vi antigen. In contrast, a cytosolic derivative had no effect unless export was disrupted. These data provide evidence that CPS assembled in ABC transporter-dependent systems is actually exposed to the periplasm during envelope translocation. | |
dc.format.extent | 10 | |
dc.format.extent | 1753382 | |
dc.language.iso | eng | |
dc.relation.ispartof | Proceedings of the National Academy of Sciences of the United States of America | en |
dc.subject | Bacterial cell surface | en |
dc.subject | Capsular polysaccharide | en |
dc.subject | Salmonella enterica | en |
dc.subject | Glycosidase | en |
dc.subject | Glycan export | en |
dc.subject | QH301 Biology | en |
dc.subject | DAS | en |
dc.subject.lcc | QH301 | en |
dc.title | Periplasmic depolymerase provides insight into ABC transporter-dependent secretion of bacterial capsular polysaccharides | en |
dc.type | Journal article | en |
dc.contributor.sponsor | The Wellcome Trust | en |
dc.contributor.institution | University of St Andrews. School of Biology | en |
dc.contributor.institution | University of St Andrews. School of Chemistry | en |
dc.contributor.institution | University of St Andrews. EaSTCHEM | en |
dc.contributor.institution | University of St Andrews. Biomedical Sciences Research Complex | en |
dc.identifier.doi | 10.1073/pnas.1801336115 | |
dc.description.status | Peer reviewed | en |
dc.identifier.grantnumber | 100209/Z/12/Z | en |
This item appears in the following Collection(s)
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.