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. 1981 Aug;78(8):4777–4781. doi: 10.1073/pnas.78.8.4777

7-Methylguanine in poly(dG-dC).poly(dG-dC) facilitates z-DNA formation.

A Möller, A Nordheim, S R Nichols, A Rich
PMCID: PMC320246  PMID: 6946426

Abstract

Poly(dG-dC).poly(dG-dC) was methylated at the N-7 position of guanine through the use of dimethyl sulfate. The conversion of poly(dG-dC).poly(dG-dC) from B-DNA to the Z-DNA form was followed by measuring both the circular dichroic spectra and changes in the absorbance ratio A295/A260. Increasing methylation steadily decreases the amount of NaCl or MgCl2 that is required to convert the polymer from B-DNA to Z-DNA. At 100% methylation of the guanine residues, the modified polymer is fully converted to Z-DNA in a physiological salt solution. Kinetic experiments show that methylation markedly accelerates the speed of the conversion from B-DNA to Z-DNA in the presence of added salt. These effects may be partly due to the positive charge on guanine that accompanies N-7 methylation.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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