STUDIES ON THE PHYSIOLOGY OF RICKETTSIAE V

Mallavia , L. (University of Kansas, Lawrence)and D. Paretsky . Studies on the physiology of rickettsiae. V. Metabolism of carbamyl phosphate byCoxiella burnetii . J. Bacteriol.86: 232–238. 1963.—Preparations of disruptedCoxiella burnetii catalyze synthesis of citrulline from ornithine and carbamyl phosphate at an optimal pH of 7.0 to 7.5. Rickettsial synthesis of the pyrimidine precursor, ureidosuccinate, is demonstrated and confirmed by isolating C14 -labeled ureidosuccinate from reaction mixtures of carbamyl phosphate and labeled aspartate. The data suggest a further rickettsial synthesis of orotate and imply rickettsial competence for host-independent pyrimidine synthesis.