title: DNA-dependent RNA polymerase from Pseudomonas aeruginosa.
abstract: DNA-dependent RNA polymerase was purified from Pseudomonas aeruginosa. The subunit structure was typical of other eubacterial RNA polymerases in having beta' (157,000), beta (148,000), sigma (87,000), and alpha 2 (45,000) subunits as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme was dependent on Mg2+, displaying optimal activity at 10 mM MgCl2. Ca2+ and Zn2+ could not replace MgCl2 in the assay system, while Mn2+, produced partial activity. KCl at concentrations greater than 10 mM inhibited enzyme activity. Optimal enzyme activity was observed at pH 8.5-9.0. The RNA polymerase was stable in 50% (w/v) glycerol at 4 degrees C for more than 3 months. Enzyme activity was inhibited in vitro by heparin, streptolydigin, streptovaracin, actinomycin D, and rifampicin.
mesh_terms: D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008274:Magnesium / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D013698:Templates, Genetic; D014158:Transcription, Genetic
chemical_list: D012321:DNA-Directed RNA Polymerases; D008274:Magnesium