Studies on gene control regions XII. The functional significance of a lac operator constitutive mutation - PubMed (original) (raw)

Studies on gene control regions XII. The functional significance of a lac operator constitutive mutation

E F Fisher et al. Nucleic Acids Res. 1979.

Free PMC article

Abstract

The functional significance of a lac operator constitutive mutation has been determined. The transition adenine-thymine to guanine-cytosine was shown to be a constitutive mutation simply because thymine contains the functionally important 5-methyl group whereas cytosine does not. The remainder of the base pair is of no consequence. The experimental approach was to synthesize various modified operators containing cytosine, 5-methyl-cytosine, and 5-bromocytosine. The synthetic operator containing a guanine-cytosine base pair displays an eightfold reduction in stability with lac repressor whereas the operator containing 5-methylcytosine binds repressor at least as tightly as does the wild type sequence. Results published previously have shown that a similar decrease in stability of the repressor-operator complex can be obtained simply by substituting uracil for thymine or by inverting the base pair to thymine-adenine. All these results taken together implicate the thymine 5-methyl as the only important functional group recognized by the lac repressor at this base pair. Further confirmation of this conclusion was obtained by substitution of 5-bromocytosine and 5-bromouracil at this base pair. Both altered the stability of the repressor-operator complex by about the same percent suggesting that the bromine atom was the important determinant of complex stability for 5-bromopyrimidine analogs.

PubMed Disclaimer

Similar articles

• Studies on gene control regions X. The effect of specific adenine-thymine transversions on the lac repressor-lac operator interaction.
  Sista HS, Loder RT, Caruthers MH. Sista HS, et al. Nucleic Acids Res. 1979 Jun 11;6(7):2583-99. doi: 10.1093/nar/6.7.2583. Nucleic Acids Res. 1979. PMID: 379824 Free PMC article.
• Origin of the asymmetrical contact between lac repressor and lac operator DNA.
  Rastinejad F, Artz P, Lu P. Rastinejad F, et al. J Mol Biol. 1993 Oct 5;233(3):389-99. doi: 10.1006/jmbi.1993.1519. J Mol Biol. 1993. PMID: 8411152
• The arginine repressor of Escherichia coli K-12 makes direct contacts to minor and major groove determinants of the operators.
  Wang H, Glansdorff N, Charlier D. Wang H, et al. J Mol Biol. 1998 Apr 10;277(4):805-24. doi: 10.1006/jmbi.1998.1632. J Mol Biol. 1998. PMID: 9545374
• Thymine methyls and DNA-protein interactions.
  Ivarie R. Ivarie R. Nucleic Acids Res. 1987 Dec 10;15(23):9975-83. doi: 10.1093/nar/15.23.9975. Nucleic Acids Res. 1987. PMID: 3320959 Free PMC article. Review.
• Synthetic oligodeoxynucleotides for analyses of DNA structure and function.
  Wu R, Bahl CP. Wu R, et al. Prog Nucleic Acid Res Mol Biol. 1978;21:101-41. doi: 10.1016/s0079-6603(08)60268-8. Prog Nucleic Acid Res Mol Biol. 1978. PMID: 358276 Review. No abstract available.

Cited by

• Methylation Motifs in Promoter Sequences May Contribute to the Maintenance of a Conserved m5C Methyltransferase in Helicobacter pylori.
  Meng B, Epp N, Wijaya W, Mrázek J, Hoover TR. Meng B, et al. Microorganisms. 2021 Nov 30;9(12):2474. doi: 10.3390/microorganisms9122474. Microorganisms. 2021. PMID: 34946076 Free PMC article.
• Uracil-DNA glycosylase defective mutants of Ustilago maydis.
  Yamamoto Y, Holliday R. Yamamoto Y, et al. Curr Genet. 1983 Jul;7(4):289-98. doi: 10.1007/BF00376074. Curr Genet. 1983. PMID: 24173339
• Determinants of bacteriophage 933W repressor DNA binding specificity.
  Bullwinkle TJ, Samorodnitsky D, Rosati RC, Koudelka GB. Bullwinkle TJ, et al. PLoS One. 2012;7(4):e34563. doi: 10.1371/journal.pone.0034563. Epub 2012 Apr 3. PLoS One. 2012. PMID: 22509323 Free PMC article.
• Inhibition of condensation in human chromosomes induced by the thymidine analogue 5-iododeoxyuridine.
  Ott G, Haaf T, Schmid M. Ott G, et al. Chromosome Res. 1998 Sep;6(6):495-9. doi: 10.1023/a:1009260714256. Chromosome Res. 1998. PMID: 9865789
• Identification of amino acid-base contacts in the Myc-DNA complex by site-specific bromouracil mediated photocrosslinking.
  Dong Q, Blatter EE, Ebright YW, Bister K, Ebright RH. Dong Q, et al. EMBO J. 1994 Jan 1;13(1):200-4. doi: 10.1002/j.1460-2075.1994.tb06249.x. EMBO J. 1994. PMID: 8306962 Free PMC article.

References

1. 1. Biochemistry. 1976 May 4;15(9):1858-65 - PubMed
2. 1. Biochemistry. 1977 May 3;16(9):1765-72 - PubMed
3. 1. Nucleic Acids Res. 1977 Sep;4(9):3039-54 - PubMed
4. 1. Proc Natl Acad Sci U S A. 1977 Aug;74(8):3292-6 - PubMed
5. 1. Nucleic Acids Res. 1979 Jun 11;6(7):2583-99 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources

• Full Text Sources

  • Europe PubMed Central
  • PubMed Central
  • Silverchair Information Systems