Structural organization of the genes that encode two glutamate synthase subunits of Escherichia coli

Plasmid pRSP20, a recombinant plasmid isolated from the Clarke-Carbon Escherichia coli gene bank, contains the two genes coding for the subunits of glutamate synthase (GOGAT). We have constructed several derivatives of pRSP20, and analyzed the direction of transcription and genetic organization of these genes. Unexpectedly, we have found that although they are tightly linked and are transcribed in the same direction, each of them has its own promoter.