Biogenesis of F7(1) and F7(2) fimbriae of uropathogenic Escherichia coli: influence of the FsoF and FstFG proteins and localization of the Fso/FstE protein.

The F7(1) and F7(2) P-fimbriae of Escherichia coli are encoded by the fso (F seven one) and fst (F seven two) gene clusters, respectively (Van Die et al., 1984; 1985). With the immunocytochemical gold-labelling technique it was demonstrated that both the FsoE and FstE proteins are non-adhesive minor fimbrial subunits located at the tip of the fimbrial structure. The FsoF and FstFG proteins play an important role in the initiation of polymerization of the minor and major subunits into the fimbrial structure.