Abstract
Three binding sites for AraC protein were shown to be required for the autoregulation of araC: araI1, araO1, and araO2. Selective inactivation of AraC-binding sites on the DNA demonstrated that araO1 and araO2 are required in vivo to produce repression of araC in the presence of arabinose, whereas araI1 and araO2 are required in its absence. We found that the low-affinity site araO2 is essential for araC autoregulation; araO1 and araI1 provide high-affinity AraC-binding sites, which allow cooperative binding at araO2. Profound effects on the araBAD promoter and the araC promoter are produced by ligand-induced changes in AraC occupancy of functional sites on the DNA. We suggest that AraC exerts its multiplicity of controls through two alternative states of cooperative interactions with DNA and we illustrate this with a model. This model presents our interpretations of activation and repression of the araBAD operon and the autoregulation of the araC gene.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Besse M., von Wilcken-Bergmann B., Müller-Hill B. Synthetic lac operator mediates repression through lac repressor when introduced upstream and downstream from lac promoter. EMBO J. 1986 Jun;5(6):1377–1381. doi: 10.1002/j.1460-2075.1986.tb04370.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Casadaban M. J. Regulation of the regulatory gene for the arabinose pathway, araC. J Mol Biol. 1976 Jul 5;104(3):557–566. doi: 10.1016/0022-2836(76)90120-0. [DOI] [PubMed] [Google Scholar]
- Dandanell G., Hammer K. Two operator sites separated by 599 base pairs are required for deoR repression of the deo operon of Escherichia coli. EMBO J. 1985 Dec 1;4(12):3333–3338. doi: 10.1002/j.1460-2075.1985.tb04085.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Deuschle U., Gentz R., Bujard H. lac Repressor blocks transcribing RNA polymerase and terminates transcription. Proc Natl Acad Sci U S A. 1986 Jun;83(12):4134–4137. doi: 10.1073/pnas.83.12.4134. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dunn T. M., Hahn S., Ogden S., Schleif R. F. An operator at -280 base pairs that is required for repression of araBAD operon promoter: addition of DNA helical turns between the operator and promoter cyclically hinders repression. Proc Natl Acad Sci U S A. 1984 Aug;81(16):5017–5020. doi: 10.1073/pnas.81.16.5017. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dynan W. S., Tjian R. Control of eukaryotic messenger RNA synthesis by sequence-specific DNA-binding proteins. 1985 Aug 29-Sep 4Nature. 316(6031):774–778. doi: 10.1038/316774a0. [DOI] [PubMed] [Google Scholar]
- ENGLESBERG E. Enzymatic characterization of 17 L-arabinose negative mutants of Escherichia coli. J Bacteriol. 1961 Jun;81:996–1006. doi: 10.1128/jb.81.6.996-1006.1961. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eismann E., von Wilcken-Bergmann B., Müller-Hill B. Specific destruction of the second lac operator decreases repression of the lac operon in Escherichia coli fivefold. J Mol Biol. 1987 Jun 20;195(4):949–952. doi: 10.1016/0022-2836(87)90499-2. [DOI] [PubMed] [Google Scholar]
- Englesberg E., Squires C., Meronk F., Jr The L-arabinose operon in Escherichia coli B-r: a genetic demonstration of two functional states of the product of a regulator gene. Proc Natl Acad Sci U S A. 1969 Apr;62(4):1100–1107. doi: 10.1073/pnas.62.4.1100. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hahn S., Dunn T., Schleif R. Upstream repression and CRP stimulation of the Escherichia coli L-arabinose operon. J Mol Biol. 1984 Nov 25;180(1):61–72. doi: 10.1016/0022-2836(84)90430-3. [DOI] [PubMed] [Google Scholar]
- Hahn S., Schleif R. In vivo regulation of the Escherichia coli araC promoter. J Bacteriol. 1983 Aug;155(2):593–600. doi: 10.1128/jb.155.2.593-600.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hawley D. K., McClure W. R. Compilation and analysis of Escherichia coli promoter DNA sequences. Nucleic Acids Res. 1983 Apr 25;11(8):2237–2255. doi: 10.1093/nar/11.8.2237. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hendrickson W., Schleif R. F. Regulation of the Escherichia coli L-arabinose operon studied by gel electrophoresis DNA binding assay. J Mol Biol. 1984 Sep 25;178(3):611–628. doi: 10.1016/0022-2836(84)90241-9. [DOI] [PubMed] [Google Scholar]
- Hochschild A., Irwin N., Ptashne M. Repressor structure and the mechanism of positive control. Cell. 1983 Feb;32(2):319–325. doi: 10.1016/0092-8674(83)90451-8. [DOI] [PubMed] [Google Scholar]
- Hochschild A., Ptashne M. Cooperative binding of lambda repressors to sites separated by integral turns of the DNA helix. Cell. 1986 Mar 14;44(5):681–687. doi: 10.1016/0092-8674(86)90833-0. [DOI] [PubMed] [Google Scholar]
- Krämer H., Niemöller M., Amouyal M., Revet B., von Wilcken-Bergmann B., Müller-Hill B. lac repressor forms loops with linear DNA carrying two suitably spaced lac operators. EMBO J. 1987 May;6(5):1481–1491. doi: 10.1002/j.1460-2075.1987.tb02390.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kuhnke G., Krause A., Heibach C., Gieske U., Fritz H. J., Ehring R. The upstream operator of the Escherichia coli galactose operon is sufficient for repression of transcription initiated at the cyclic AMP-stimulated promoter. EMBO J. 1986 Jan;5(1):167–173. doi: 10.1002/j.1460-2075.1986.tb04192.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee J. H., Burke K., Wilcox G. Mutations resulting in promoter-like sequences which enhance the expression of araC in Salmonella typhimurium. Gene. 1986;46(1):113–121. doi: 10.1016/0378-1119(86)90173-3. [DOI] [PubMed] [Google Scholar]
- Lee N. L., Gielow W. O., Wallace R. G. Mechanism of araC autoregulation and the domains of two overlapping promoters, Pc and PBAD, in the L-arabinose regulatory region of Escherichia coli. Proc Natl Acad Sci U S A. 1981 Feb;78(2):752–756. doi: 10.1073/pnas.78.2.752. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee N., Francklyn C., Hamilton E. P. Arabinose-induced binding of AraC protein to araI2 activates the araBAD operon promoter. Proc Natl Acad Sci U S A. 1987 Dec;84(24):8814–8818. doi: 10.1073/pnas.84.24.8814. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lichenstein H. S., Hamilton E. P., Lee N. Repression and catabolite gene activation in the araBAD operon. J Bacteriol. 1987 Feb;169(2):811–822. doi: 10.1128/jb.169.2.811-822.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Liu-Johnson H. N., Gartenberg M. R., Crothers D. M. The DNA binding domain and bending angle of E. coli CAP protein. Cell. 1986 Dec 26;47(6):995–1005. doi: 10.1016/0092-8674(86)90814-7. [DOI] [PubMed] [Google Scholar]
- Majumdar A., Adhya S. Demonstration of two operator elements in gal: in vitro repressor binding studies. Proc Natl Acad Sci U S A. 1984 Oct;81(19):6100–6104. doi: 10.1073/pnas.81.19.6100. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Martin K., Huo L., Schleif R. F. The DNA loop model for ara repression: AraC protein occupies the proposed loop sites in vivo and repression-negative mutations lie in these same sites. Proc Natl Acad Sci U S A. 1986 Jun;83(11):3654–3658. doi: 10.1073/pnas.83.11.3654. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miyada C. G., Horwitz A. H., Cass L. G., Timko J., Wilcox G. DNA sequence of the araC regulatory gene from Escherichia coli B/r. Nucleic Acids Res. 1980 Nov 25;8(22):5267–5274. doi: 10.1093/nar/8.22.5267. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mossing M. C., Record M. T., Jr Upstream operators enhance repression of the lac promoter. Science. 1986 Aug 22;233(4766):889–892. doi: 10.1126/science.3090685. [DOI] [PubMed] [Google Scholar]
- Ogden S., Haggerty D., Stoner C. M., Kolodrubetz D., Schleif R. The Escherichia coli L-arabinose operon: binding sites of the regulatory proteins and a mechanism of positive and negative regulation. Proc Natl Acad Sci U S A. 1980 Jun;77(6):3346–3350. doi: 10.1073/pnas.77.6.3346. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ptashne M. Gene regulation by proteins acting nearby and at a distance. Nature. 1986 Aug 21;322(6081):697–701. doi: 10.1038/322697a0. [DOI] [PubMed] [Google Scholar]
- Reznikoff W. S., Siegele D. A., Cowing D. W., Gross C. A. The regulation of transcription initiation in bacteria. Annu Rev Genet. 1985;19:355–387. doi: 10.1146/annurev.ge.19.120185.002035. [DOI] [PubMed] [Google Scholar]
- Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shimada K., Weisberg R. A., Gottesman M. E. Prophage lambda at unusual chromosomal locations. II. Mutations induced by bacteriophage lambda in Escherichia coli K12. J Mol Biol. 1973 Oct 25;80(2):297–314. doi: 10.1016/0022-2836(73)90174-5. [DOI] [PubMed] [Google Scholar]
- Struhl K. Promoters, activator proteins, and the mechanism of transcriptional initiation in yeast. Cell. 1987 May 8;49(3):295–297. doi: 10.1016/0092-8674(87)90277-7. [DOI] [PubMed] [Google Scholar]
- Tuggle C. K., Fuchs J. A. Regulation of the operon encoding ribonucleotide reductase in Escherichia coli: evidence for both positive and negative control. EMBO J. 1986 May;5(5):1077–1085. doi: 10.1002/j.1460-2075.1986.tb04325.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Valentin-Hansen P., Albrechtsen B., Løve Larsen J. E. DNA-protein recognition: demonstration of three genetically separated operator elements that are required for repression of the Escherichia coli deoCABD promoters by the DeoR repressor. EMBO J. 1986 Aug;5(8):2015–2021. doi: 10.1002/j.1460-2075.1986.tb04458.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wilcox G. The interaction of L-arabinose and D-fucose with AraC protein. J Biol Chem. 1974 Nov 10;249(21):6892–6894. [PubMed] [Google Scholar]
- Zoller M. J., Smith M. Oligonucleotide-directed mutagenesis of DNA fragments cloned into M13 vectors. Methods Enzymol. 1983;100:468–500. doi: 10.1016/0076-6879(83)00074-9. [DOI] [PubMed] [Google Scholar]