Expression of the Rickettsia prowazekii citrate synthase gene in Escherichia coli

Recombinant DNA techniques were used to isolate the Rickettsia prowazekii citrate synthase gene on the plasmid vector pBR322 by functional complementation of a gltA mutation of Escherichia coli K-12. Analysis of citrate synthase activity in crude extracts revealed that the enzyme expressed in E. coli retains the regulatory control mechanisms characteristic of the rickettsial enzyme.