The E.Coli derived recombinant 6xHis tag fusion protein is a multimer having a molecular mass of 48kDa and contains the Trp. Pallidum p15 immunodominant regions and six histidines fused at the C- terminus.
Treponema pallidum is a gram-negative spirochaete bacterium and is considered to be metabolically crippled. There are at least four known subspecies: T. pallidum pallidum, T. pallidum pertenue, T. pallidum carateum and T. pallidum endemicum. The helical structure of T. pallidum pallidum allows it to move in a corkscrew motion throµgh viscous mediums such as mucus. Treponema pallidum sub sp. pallidum has one of the smallest bacterial genomes at 1.14 million base pairs (Mb) and has limited metabolic capabilities, reflecting its adaptation throµgh genome reduction to the rich environment of mammalian tissue.