CHIMERIC FIMH ADHESIN OF TYPE-1 FIMBRIAE - A BACTERIAL SURFACE DISPLAY SYSTEM FOR HETEROLOGOUS SEQUENCES

The FimH adhesin of type 1 fimbriae has been tested as a display syste m for heterologous protein segments on the surface of Escherichia coli , This was carried out by introduction of restriction site handles (Bg /II sites) in two different positions in the fimH gene, followed by in -frame insertion of heterologous DNA segments encoding two reporter se quences. In the selected positions such insertions did not significant ly alter the function of the FimH protein with regard to surface locat ion and adhesive ability. The system seemed to be quite flexible, sinc e chimeric versions of the FimH adhesin containing as many as 56 forei gn amino acids were transported to the bacterial surface as components of the fimbrial organelles. Furthermore, the foreign protein segments were recognized by insert-specific antibodies when expressed within c himeric proteins on the surface of the bacteria, The results from this feasibility study point to the possibility of using the FimH adhesin as a general surface display system for sizeable protein segments.