The genetic determinant of adhesive function in type 1 fimbriae of Escherichia coli is distinct from the gene encoding the fimbrial subunit.

摘要: The role of type 1 fimbriae in the mannose-sensitive attachment Escherichia coli to eucaryotic cells was investigated by deletion mutation analysis a recombinant plasmid, pSH2, carrying genetic information for synthesis and expression functional fimbriae. A mutant, pUT2002, containing remote from structural gene encoding 17-kilodalton subunit protein failed agglutinate guinea pig erythrocytes even though bacteria expressed morphologically antigenically indistinguishable those produced intact plasmid. Fimbriae isolated pUT2002 erythrocytes, but reacted with monoclonal antibody specific quaternary determinants Moreover, dissociated fimbrial subunits this mutant were normal their migration during electrophoresis sodium dodecyl sulfate-polyacrylamide gels, reactivity directed against subunit-specific epitope, enzyme-linked immunosorbent assays monospecific antisera. These results indicate that adhesive functions are dependent on factor(s) encoded other than required synthesis, assembly, subunit.