Analysis of the Spirochaeta aurantia flaA gene and transcript.

The flaA gene, which codes for the Spirochaeta aurantia flagellar filament outer layer polypeptide, FlaA, was cloned, sequenced and analysed. The gene appears to be transcribed into a monocistronic mRNA from a sigma 70-like promoter. The translational start is 31 base pairs after the start of the transcript, the open reading frame is 1011 base pairs, and a rho-independent-like transcription terminator sequence begins about 19 base pairs after the translational stop codon. The deduced amino acid sequence of the S. aurantia FlaA showed 40% identity with the Treponema pallidum FlaA, but these polypeptides did not show a significant similarity to other polypeptides for which sequence information was available.