MOLECULAR CHARACTERIZATION OF TREPONEMA-PALLIDUM MCP2, A PUTATIVE CHEMOTAXIS PROTEIN GENE

The nucleotide sequence of the Treponema pallidum mcp2 gene was determ ined. mcp2 encodes a 45.8-kDa protein whose deduced amino acid sequenc e has significant homology with the C-terminal region of bacterial met hyl-accepting chemotaxis proteins (MCPs). The Mcpa N terminus lacks th e hydrophobic transmembrane regions present in most MCPs. An Mcp2 fusi on protein was strongly reactive,vith antibody (HC23) to the highly co nserved domain of MCPs and with rabbit syphilitic serum. Antibody HC23 reacted with six T. pallidum proteins, including a 45-kDa protein tha t may correspond to Mcp2. This protein was present in the aqueous phas e from T. pallidum cells that were solubilized with Triton X-114 and p hase partitioned.