Abstract
The thermal stability of the Tn10 encoded tetracycline resistance (TET) gene control region is investigated by melting studies using purified DNA restriction fragments containing various amounts of flanking sequences. In order to study the thermodynamic properties of this control region under conditions, where enough flanking DNA is present to mimic the situation in the chromosome, the five step melting process of a 1450-bp DNA fragment is analyzed. Because most of the sequence of this DNA is not known, the assignment of the melting transitions to segments of the DNA is done by an experimental method. This employs the preparation of subfragments from the 1450-bp DNA and comparison of their denaturation profiles with the one of the intact sequence. This approach results in the complete assignment of the five denaturation steps. Rather than from the ends, the unwinding starts from the TET gene control region in the middle of the 1450-bp sequence. A clear correlation between the thermodynamic and genetic properties of this DNA is observed. The regulatory sequence forms a small cooperative unit with the lowest stability in the entire fragment. The thermal denaturation of the TET repressor. TET operator complex reveals, that the TET repressor specifically recognizes the double stranded TET operator DNA and stabilizes this structure by 2.4 degrees C. This results is also discussed as an example of the possible action of denaturing or stabilizing proteins on this genetic control region.
Full text
PDF















Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Azbel M. Y. DNA sequencing and helix-coil transition. III. DNA sequencing. Biopolymers. 1980 Jan;19(1):95–109. doi: 10.1002/bip.1980.360190107. [DOI] [PubMed] [Google Scholar]
- Benight A. S., Wartell R. M., Howell D. K. Theory agrees with experimental thermal denaturation of short DNA restriction fragments. Nature. 1981 Jan 15;289(5794):203–205. doi: 10.1038/289203a0. [DOI] [PubMed] [Google Scholar]
- Blake R. D., Lefoley S. G. Spectral analysis of high resolution direct-derivative melting curves of DNA for instantaneous and total base composition. Biochim Biophys Acta. 1978 Apr 27;518(2):233–246. doi: 10.1016/0005-2787(78)90180-6. [DOI] [PubMed] [Google Scholar]
- Gotoh O., Tagashira Y. Locations of frequently opening regions on natural DNAs and their relation to functional loci. Biopolymers. 1981 May;20(5):1043–1058. doi: 10.1002/bip.1981.360200514. [DOI] [PubMed] [Google Scholar]
- Greene P. J., Heyneker H. L., Bolivar F., Rodriguez R. L., Betlach M. C., Covarrubias A. A., Backman K., Russel D. J., Tait R., Boyer H. W. A general method for the purification of restriction enzymes. Nucleic Acids Res. 1978 Jul;5(7):2373–2380. doi: 10.1093/nar/5.7.2373. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hardies S. C., Hillen W., Goodman T. C., Wells R. D. High resolution thermal denaturation analyses of small sequenced DNA restriction fragments containing Escherichia coli lactose genetic control loci. J Biol Chem. 1979 Oct 25;254(20):10128–10134. [PubMed] [Google Scholar]
- Hillen W., Goodman T. C., Wells R. D. Salt dependence and thermodynamic interpretation of the thermal denaturation of small DNA restriction fragments. Nucleic Acids Res. 1981 Jan 24;9(2):415–436. doi: 10.1093/nar/9.2.415. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hillen W., Klein R. D., Wells R. D. Preparation of milligram amounts of 21 deoxyribonucleic acid restriction fragments. Biochemistry. 1981 Jun 23;20(13):3748–3756. doi: 10.1021/bi00516a013. [DOI] [PubMed] [Google Scholar]
- Jones B. B., Chan H., Rothstein S., Wells R. D., Reznikoff W. S. RNA polymerase binding sites in lambdaplac5 DNA. Proc Natl Acad Sci U S A. 1977 Nov;74(11):4914–4918. doi: 10.1073/pnas.74.11.4914. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jorgensen R. A., Reznikoff W. S. Organization of structural and regulatory genes that mediate tetracycline resistance in transposon Tn10. J Bacteriol. 1979 Jun;138(3):705–714. doi: 10.1128/jb.138.3.705-714.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lyubchenko Y. L., Vologodskii A. V., Frank-Kamenetskii M. D. Direct comparison of theoretical and experimental melting profiles for RF II phiX174 DNA. Nature. 1978 Jan 5;271(5640):28–31. doi: 10.1038/271028a0. [DOI] [PubMed] [Google Scholar]
- Scherer G. E., Walkinshaw M. D., Arnott S. A computer aided oligonucleotide analysis provides a model sequence for RNA polymerase-promoter recognition in E.coli. Nucleic Acids Res. 1978 Oct;5(10):3759–3773. doi: 10.1093/nar/5.10.3759. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Siebenlist U., Simpson R. B., Gilbert W. E. coli RNA polymerase interacts homologously with two different promoters. Cell. 1980 Jun;20(2):269–281. doi: 10.1016/0092-8674(80)90613-3. [DOI] [PubMed] [Google Scholar]
- Wada A., Tachibana H., Gotoh O., Takanami M. Long range homogeneity of physical stability in double-stranded DNA. Nature. 1976 Sep 30;263(5576):439–440. doi: 10.1038/263439a0. [DOI] [PubMed] [Google Scholar]
- Wada A., Tachibana H., Ueno S., Husimi Y., Machida Y. Melting fine structure of DNA fragments of known base sequence from theta X174. Nature. 1977 Sep 22;269(5626):352–353. doi: 10.1038/269352a0. [DOI] [PubMed] [Google Scholar]
- Wells R. D., Hardies S. C., Horn G. T., Klein B., Larson J. E., Neuendorf S. K., Panayotatos N., Patient R. K., Selsing E. RPC-5 column chromatography for the isolation of DNA fragments. Methods Enzymol. 1980;65(1):327–347. doi: 10.1016/s0076-6879(80)65043-5. [DOI] [PubMed] [Google Scholar]
- Wray L. V., Jr, Jorgensen R. A., Reznikoff W. S. Identification of the tetracycline resistance promoter and repressor in transposon Tn10. J Bacteriol. 1981 Aug;147(2):297–304. doi: 10.1128/jb.147.2.297-304.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
