IDENTIFICATION AND SEQUENCES OF THE TREPONEMA-PALLIDUM FLHA, FLHF, AND ORF304 GENES

The recently identified fla operon of Treponema pallidum contains seve ral genes that encode motility-related proteins. We have determined th e nucleotide sequences of three genes, designated flhA, flhF, and orf3 04, that are located immediately downstream of the flhB gene in the fl a operon. The flhA gene encodes a 707-amino acid protein that contains five putative membrane spanning domains. FlhA has strong homology wit h members of a family of proteins that are involved in flagellar bioge nesis and regulation/secretion of virulence-related proteins. The flhF gene encodes a 437-amino acid protein that contains three consensus e lements that are characteristic of a GTP-binding domain. The orf304 ge ne encodes a 304-amino acid protein that contains a consensus ATP-bind ing motif. The order of the flhA, flhF, and orf304 genes is identical to that of corresponding genes in the Bacillus subtilis che/fla operon . Due to the location of the flhA, flhF and orf304 genes in the T. pal lidum pa operon, we hypothesize that the FLhA, FLhF, and Orf304 protei ns are involved in the biogenesis/assembly of treponemal periplasmic f lagella.