Activation of Transcription at Specific Promoters by Glycerol

作者：Shigetada Nakanishi, Sankar L Adhya, Max E. Gottesman, Ira H Pastan · 发表于：Journal of Biological Chemistry · 年份：1974 · DOI：10.1016/s0021-9258(19)42482-4 · 被引用次数：95 · 研究领域：Bacterial Genetics and Biotechnology、DNA and Nucleic Acid Chemistry、Escherichia coli research studies

Abstract Glycerol added to a transcription system containing λgal DNA and Escherichia coli RNA polymerase holoenzyme stimulates total RNA synthesis and replaces the requirement for cyclic adenosine 3' : 5'-monophosphate (cAMP) and cAMP receptor (CRP) for promotion of gal RNA synthesis. The stimulatory effect which is proportional to the concentration of glycerol up to 20% (v/v) occurs at the level of preinitiation complex formation. In stimulating gal transcription, glycerol appears to act at or close to the same site as cAMP and CRP because: (a) glycerol has little effect on gal transcription at saturating levels of cAMP and CRP; (b) although glycerol stimulates transcription from λgal DNA bearing revertible gal promoter mutations, transcription from DNA containing a gal promoter deletion is not stimulated; (c) glycerol stimulation of gal promoter mutants is inhibited by cAMP and CRP; and (d) with either glycerol or cAMP and CRP, transcription of the promoter-proximal galE region precedes transcription of the galKT region. The effect of glycerol on λ early transcription is to stimulate early r-strand RNA synthesis but not early l-strand RNA synthesis. However, if the DNA template contains a defective λsex promoter, the decreased levels of early l-strand RNA are restored to normal by glycerol. Ethylene glycol, dimethylsulfoxide, sucrose, and 1,3-propanediol, all of which lower the Tm of DNA, also stimulate both total RNA and gal RNA synthesis. Furthermore, the glycerol-promot...