Cloning and expression of a pili gene of Corynebacterium renale in Escherichia coli.

A plasmid gene library of Corynebacterium renale piliated strain No. 109P+ was prepared in Escherichia coli in order to study the chemical structure of the pili of C. renale. Of 3,000 recombinant clones tested, 5 reacted with anti-pili anti-serum. The gene products of these clones reacted with anti-pili monoclonal antibodies 8/4, 5/2 and B20/3 but lacked the reactivity with 13/4. SDS-PAGE analysis revealed that the expressed protein had a molecular mass of 48 kilodalton and deletion analysis showed that the encoding region for this protein was localized within a 1.4 kilobase gene including a promoter sequence. Immunoelectron microscopy showed that mouse antibodies raised to the expressed protein bound to the entire surface of the pili of C. renale. These results indicate that the cloned gene encodes a major structural protein of C. renale pili.