Streptomyces lividans RNA polymerase recognizes and uses Escherichia coli transcriptional signals.

We report here the use of a novel genetic approach for the study of transcriptional control in Streptomyces lividans. Using up-promoter mutants of the ampC beta-lactamase gene of Escherichia coli, we have shown that mutations in each of the regions that define the major determinants of promoter strength in E. coli-i.e., the -35 region, the -10 region, and the intervening "spacer" region-lead to increased synthesis of ampC mRNA in S. lividans, just as they do in their host of origin. Results are also presented showing that the ampC transcriptional terminator is functional in S. lividans. Taken together, these findings indicate that Streptomyces have an RNA polymerase that recognizes and uses the various components of E. coli transcriptional signals, and imply that, notwithstanding the high GC content (i.e., 73%) of the Streptomyces genome, these organisms have indigenous promoters similar to those found in E. coli.