Tricistronic operon expression of the genes gcaD (tms), which encodes N-acetylglucosamine 1-phosphate uridyltransferase, prs, which encodes phosphoribosyl diphosphate synthetase, and ctc in vegetative cells of Bacillus subtilis.

The gcaD, prs, and ctc genes were shown to be organized as a tricistronic operon. The transcription of the prs gene, measured as phosphoribosyl diphosphate synthetase activity, and of the ctc gene, measured as beta-galactosidase activity specified by a ctc-lacZ protein fusion, were dependent on the promoter in front of the gcaD gene. Analysis of cDNA molecules prepared with gcaD-prs-ctc-specified mRNA as the template revealed an RNA transcript that encompassed all three cistrons.