Molecular Characterization of the Treponema denticola fliQ Region

Abstract

A Treponema denticola 4.2 kb DNA region containing four complete genes (orf1, fliQ, fliR, and flhB) and a truncated gene (flhA1) was sequenced and analyzed. The deduced amino acid sequences of FliQ, FliR, FlhB and FlhA' have significant homology with bacterial proteins associated with the flagellar export apparatus, whereas the deduced amino acid sequence of Orfl has homology with an E. coli alcohol dehydrogenase. A putative α70-like promoter was identified upstream of fliQ. RT-PCR analysis indicated that fliQ, fliR, flhB and flhA1 are co-transcribed independently of orfl, suggesting that the motility-associated genes are components of an operon. The location of the T. denticola fliQ-flhA1 genes differs from that of the corresponding T. pallidum and Borrelia burgdorferi genes which are present in the large fla or flgB flagellar operons, respectively.