Identification of the RpmF-plsX-fabH Genes of Rhodobacter Capsulatus

The rpmF-plsX-fabH gene cluster of Rhodobacter capsulatus homologous to that of Escherichia coli was identified. rpmF encodes ribosomal protein L32, plsX plays an undefined role in membrane lipid synthesis, and fabH encodes beta-ketoacyl-acyl carrier protein synthase III. The R. capsulatus plsX gene complemented a defect in an E. coli strain with the plsX50 mutation. Overproduction of the fabH gene product of R. capsulatus in E. coli resulted in dramatically increased beta-ketoacyl-acyl carrier protein synthase III activity. These results indicate that plsX and fabH apparently function the same in R. capsulatus as in E. coli.