Cloning and Expression of the Gene Encoding the 32-kDa Protein of Rickettsia typhi

ABSTRACT

The crystalline surface layer protein (SLP) and a 28-32 kDa antigen of Rickettsia typhi were known as strong immunogens. We previously reported a cloning and sequence analysis of the SLP gene of R. typhi (slpT) and showed that the open reading frame of this gene encodes both the SLP and a 32-kDa protein. Our study also showed that a 48-kDa protein reacted strongly with polyclonal antiserum of a patient with murine typhus. In this study, we produced three recombinant proteins (SLP, 32-kDa, and 48-kDa protein) in E. coli as fusion proteins with maltose binding proteins. The reactivity of these proteins with patients' sera was investigated.