Is DNA unwound by the cyclic AMP receptor protein?
Superhelical pBR 322 derivatives have been relaxed by eukaryotic topoisomerase I in the presence or in the absence of E. coli cyclic AMP receptor protein (CRP) and of cyclic AMP (cAMP). CRP alone, or cAMP alone do not affect the average linking number of the distribution of the relaxed topoisomers. Hence, they do not unwind the template. In the presence of cAMP, CRP induces a small unwinding. The extent of this unwinding is barely modified when the relaxation is carried out on a similar vector plasmid where the CRP binding site of the lac or of the gal operon has been inserted. Under these conditions, we checked that CRP occupies the lactose control site and that upon addition of RNA polymerase, the corresponding promoter is readily activated. These findings are difficult to reconcile with the proposal that activation of these promoters results from the binding of the CRP-cAMP complex to left-handed DNA sequences.
27 references, click to expand
-
Effect of DNA length on the free energy of binding of an unwinding ligand to a supercoiled DNA.J Mol Biol. 1972 May 14;66(2):307-9 PMID: 5038457
-
Genetic regulation: the Lac control region.Science. 1975 Jan 10;187(4171):27-35 PMID: 1088926
-
Specific binding of CAP factor to lac promoter DNA.Nature. 1975 Aug 21;256(5519):672-4 PMID: 1097944
-
Folding of the DNA double helix in chromatin-like structures from simian virus 40.Proc Natl Acad Sci U S A. 1975 May;72(5):1843-7 PMID: 168578
-
Conformational fluctuations of DNA helix.Proc Natl Acad Sci U S A. 1975 Nov;72(11):4275-9 PMID: 172901
-
Determination of the number of superhelical turns in simian virus 40 DNA by gel electrophoresis.Proc Natl Acad Sci U S A. 1975 Dec;72(12):4876-80 PMID: 174079
-
Polynucleotide kinase exchange reaction: quantitave assay for restriction endonuclease-generated 5'-phosphoroyl termini in DNA.J Biol Chem. 1977 May 25;252(10):3176-84 PMID: 16886
-
The problems of eukaryotic and prokaryotic DNA packaging and in vivo conformation posed by superhelix density heterogeneity.Nucleic Acids Res. 1977;4(5):1183-205 PMID: 197488
-
Physiochemical studies on interactions between DNA and RNA polymerase. Unwinding of the DNA helix by Escherichia coli RNA polymerase.Nucleic Acids Res. 1977;4(5):1225-41 PMID: 331252
-
Contacts between the lac repressor and the thymines in the lac operator.Proc Natl Acad Sci U S A. 1977 Nov;74(11):4973-6 PMID: 270732
-
DNAse footprinting: a simple method for the detection of protein-DNA binding specificity.Nucleic Acids Res. 1978 Sep;5(9):3157-70 PMID: 212715
-
Modulation of gene expression by drugs affecting deoxyribonucleic acid gyrase.J Bacteriol. 1979 Apr;138(1):40-7 PMID: 108253
-
E. coli DNA binding protein HU forms nucleosomelike structure with circular double-stranded DNA.Cell. 1979 Jun;17(2):265-74 PMID: 222478
-
Complete nucleotide sequence of the Escherichia coli plasmid pBR322.Cold Spring Harb Symp Quant Biol. 1979;43 Pt 1:77-90 PMID: 383387
-
Cyclic AMP as a modulator of polarity in polycistronic transcriptional units.Proc Natl Acad Sci U S A. 1979 Jul;76(7):3194-7 PMID: 226959
-
Nicking-closing enzyme assembles nucleosome-like structures in vitro.Proc Natl Acad Sci U S A. 1979 Aug;76(8):3779-83 PMID: 226980
-
Non-specific interactions of CRP from E. coli with native and denatured DNAs: control of binding by cAMP and cGMP and by cation concentration.Nucleic Acids Res. 1979 Nov 24;7(6):1699-712 PMID: 228253
-
Interaction site of Escherichia coli cyclic AMP receptor protein on DNA of galactose operon promoters.Proc Natl Acad Sci U S A. 1979 Oct;76(10):5090-4 PMID: 228278
-
Sequencing end-labeled DNA with base-specific chemical cleavages.Methods Enzymol. 1980;65(1):499-560 PMID: 6246368
-
Binding of CRP to DNA-dependent RNA polymerase from E. coli: modulation by cAMP of the interactions with free and DNA-bound holo and core enzyme.Mol Biol Rep. 1980 Mar 31;6(1):39-43 PMID: 6248768
-
A simplified ultrasensitive silver stain for detecting proteins in polyacrylamide gels.Anal Biochem. 1980 Jul 1;105(2):361-3 PMID: 6161559
-
Cyclic AMP receptor proteins interacts with lactose operator DNA.Nucleic Acids Res. 1981 Jan 24;9(2):277-92 PMID: 6259624
-
Structure of catabolite gene activator protein at 2.9 A resolution suggests binding to left-handed B-DNA.Nature. 1981 Apr 30;290(5809):744-9 PMID: 6261152
-
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):752-6 PMID: 6262769
-
Molecuar model of the DNA interaction site for the cyclic AMP receptor protein.Proc Natl Acad Sci U S A. 1981 Apr;78(4):2213-7 PMID: 6941280
-
A promoter of pBR322 activated by cAMP receptor protein.Nucleic Acids Res. 1981 Jul 24;9(14):3365-77 PMID: 6269081
-
Mechanism for transcriptional action of cyclic AMP in Escherichia coli: entry into DNA to disrupt DNA secondary structure.Proc Natl Acad Sci U S A. 1981 Jul;78(7):4011-5 PMID: 6270652
Contact
No. 2 Wenbo Road, Zhangqiu District, Jinan, Shandong
Qilu Normal University · Genelibs Bioinformatics Lab
750 Shunhua Rd, Jinan
2F, Bldg F, University Science Park
Tel: 0531-88819269
WeChat Official Account
Follow our WeChat subscription account for real-time updates and the latest in medical and biological research.
Business Email
E-mail: [email protected]
Copyright © 2026.Genelibs Jinan Honghui Biotechnology Co., Ltd. 鲁ICP备20007159号-2
