Figure 2.

(A) Growth of the S. coelicolor strains containing promoter probe constructs. Growth was measured as the increase in optical density at 450 nm. The arrows in the figure indicate the onset of the production of two of the secondary metabolites synthesized by S. coelicolor, undecylprodigiosin (red) and actinorhodin (act). (B) Catechol dioxygenase (CATO₂ase) activity of mycelial extracts of S. coelicolor derivatives containing the putative rpsOA and rpsOB promoters, cloned in the promoter probe vector pIPP2 [35]. Mycelium was harvested at the indicated times, disrupted by sonication, and following centrifugation, supernatants were assayed for catechol dioxygenase, as described previously [31,35]. The catechol dioxygenase gene is the reporter in the promoter probe vector [35]. (C) CATO₂ase activities of extracts of strains containing the putative pnpA and pnpB promoters. The results shown are the averages of duplicate assays from two independent experiments ± SEM. This figure is reprinted from Gene, 536, Patricia Bralley, Marcha L. Gatewood, George H. Jones, Transcription of the rpsO–pnp operon of Streptomyces coelicolor involves four temporally regulated, stress responsive promoters. 177–185, Copyright (2014), with permission from Elsevier [31].