Chaperone Dependent Assembly and Structure of a Bacterial Polypeptide Capsule

F1 capsule is a polymer of a single subunit assembled on the surface of Yersinia pestis by the chaperone/usher pathway. Having blocked polymerisation of subunit and produced for the first time stable binary chaperone:subunit complex, the three-dimensional structure of the complex will be solved by X-ray crystallography. Polymer structure will be investigated by mass spectrometry, atomic force microscopy and crystallisation of mutants producing stable ternary chaperone:subunit2 complex. Mutagenesis will complement structural studies and be used to create stable subunit monomer. <P>
Results will provide detail on folding and polymerisation of relevance to all of this subfamily of adhesive organelles, including those of pathogenic E. coli and Salmonella spp.