MOLECULAR CHARACTERIZATION OF A FLAGELLAR CHEMOTAXIS OPERON IN THE SPIROCHETE BORRELIA-BURGDORFERI/

A chemotaxis gene cluster from Borrelia burgdorferi, the spirochete th at causes Lyme disease, was cloned, sequenced, and analyzed. This clus ter contained three chemotaxis gene homologs (cheA, cheW and cheY) and an open reading frame we identified as cheX. Although the major funct ional domains for B. burgdorferi CheW and CheY were well conserved, th e size of cheW was significantly different from the homolog of other b acteria. Phylogenetic analysis of CheY indicated that B. burgdorferi c onstitutes a distinct branch with Treponema pallidum and is closely as sociated with Archea and Gram-positive bacteria. RT-PCR analysis indic ated that the chemotaxis genes and the upstream flagellar gene flaA co nstitute an operon. Western blot analysis using antibody to Escherichi a coli CheA resulted in two reactive proteins in the cell lysates of B . burgdorferi that is consistent with two cheA homologs being present in this organism. The results taken together suggest both similarities and differences in the chemotaxis apparatus of B. burgdorferi compare d to those of other bacteria.