actively engaged in transcription 20 - 30: inactive 70 - 80 % of total RNA pol
||Bacteria Escherichia coli
||Churchward G, Bremer H, Young R. Transcription in bacteria at different DNA concentrations. J Bacteriol. 1982 May150(2):572-81. p.572 right column top paragraphPubMed ID6175615
||Shepherd NS, Churchward G, Bremer H. Synthesis and activity of ribonucleic acid polymerase in Escherichia coli. J Bacteriol. 1980 Mar141(3):1098-108.PubMed ID6154044
||Abstract:"The effect of changing the DNA concentration on RNA synthesis, protein synthesis, and cell growth rate was studied in Escherichia coli B/r. The DNA concentration was varied by changing the replication velocity or by changing replication initiation in a thymine-requiring strain with a mutation in replication control."
||p.115 left column bottom paragraph:”[Investigators] have previously studied the properties of a mutant of Escherichia coli B/r, strain TJK16, which has a lower DNA concentration than its wild-type parent due to a mutationally altered control of initiation of chromosome replication (refs 10, 12). TJK16 is auxotrophic for thymine, and its DNA concentration can be further lowered by growing it at low thymine concentrations (ref 12). Therefore, this strain is useful for studying the effects of varying DNA concentration on the rate of in vivo transcription. The results suggest that in both B/r and TJK16, DNA is transcribed under conditions of DNA excess i.e., transcription is limited by the concentration of active RNA polymerase rather than by DNA. In E. coli only 20 to 30% of the total RNA polymerase enzyme is actively engaged in transcription (RNA chain elongation) at any given time, whereas 70 to 80% of the RNA polymerase appears to be inactive (primary source).”