MOLECULAR-CLONING OF THE S-LAYER PROTEIN GENE OF CAMPYLOBACTER-RECTUSATCC-33238

A genomic DNA library of Campylobacter rectus (Wolinella recta) ATCC 3 3238 was constructed using bacteriophage lambda EMBL3 as a vector. One clone expressing the S-laver protein was identified immunologically w ith the antiserum to the S-layer protein of C. rectus ATCC 33238. West ern immunoblotting using monoclonal antibodies directed against the S- layer protein showed a single blot of recombinant protein at 150 kDa, suggesting that this clone contained the entire coding region of the S -layer protein gene. Additionally, the S-layer protein gene was subclo ned into plasmid vector pUC18. Southern hybridization revealed that th e S-layer protein gene was present on the chromosome of C. rectus as a single-copy gene, and that there were minor heterogeneities among the S-layer protein genes of clinical isolates. Moreover, a spontaneous s table mutant strain, which has no S-layer expression, also conserved t he full-length gene of the S-layer protein.