title: The structure of Yersinia pestis Caf1 polymer in free and adjuvant bound states.
abstract: Caf1 of the plague bacterium, Yersinia pestis is a polymeric virulence factor and vaccine component, formed from monomers by a donor strand exchange (DSE) mechanism. Here, EM images of Caf1 reveal flexible polymers up to 1.5 microm long (4MDa). The bead-like structures along the polymer are 5.8 + or - 1 nm long and correspond to single Caf1 proteins. Short polymers often form circles, presumably by DSE. We also provide the first images of proteins bound to alhydrogel adjuvant. Caf1, hemocyanin and anthrax PA are all resolved clearly and Caf1 exhibits adjuvant bound stretches with long intervening loops draped from the edges.
authors.affiliation: Institute for Cell and Molecular Sciences, Newcastle University, Framlington Place, Newcastle-upon-Tyne, NE2 4HH, UK.
authors.forename: Andrei
authors.initials: A
authors.lastname: Soliakov
authors.forename: J Robin
authors.initials: JR
authors.lastname: Harris
authors.forename: Allan
authors.initials: A
authors.lastname: Watkinson
authors.forename: Jeremy H
authors.initials: JH
authors.lastname: Lakey
mesh_terms: D000276:Adjuvants, Immunologic; D000942:Antigens, Bacterial / Q000737:chemistry* / Q000276:immunology / Q000648:ultrastructure; D016667:Bacterial Capsules / Q000737:chemistry / Q000276:immunology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000276:immunology / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D010930:Plague / Q000517:prevention & control; D010931:Plague Vaccine / Q000276:immunology; D011108:Polymers / Q000737:chemistry*; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D037521:Virulence Factors / Q000737:chemistry* / Q000276:immunology; D015010:Yersinia pestis / Q000737:chemistry / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D010931:Plague Vaccine; D011108:Polymers; D037521:Virulence Factors; C086725:caf1 protein, Yersinia pestis