7-Methylguanine in poly(dG-dC).poly(dG-dC) facilitates z-DNA formation.
Year: 1981
Type: article
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.
Authors: A Möller, A Nordheim, S R Nichols, A Rich
Institution: Massachusetts Institute of Technology
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W2064478917