Actions of the Klenow fragment of DNA polymerase I and some DNA glycosylases on chemically stable analogues of N7-methyl-2'-deoxyguanosine.
Bioorg Med Chem
; 21(22): 6886-92, 2013 Nov 15.
Article
em En
| MEDLINE
| ID: mdl-24100157
ABSTRACT
N7-methyl-9-deaza-dG was synthesized and incorporated into oligonucleotides. Thermal melting studies showed that replacement of dG by N7-methyl-9-deaza-dG only slightly decreased DNA duplex stability. Replication of DNA templates containing N7-methyl-9-deaza-dG and the related 7-methyl-7-deaza-dG and 7-deaza-dG by the Klenow fragment of Escherichia coli DNA polymerase I was examined. The dNTP misinsertion frequencies on all three templates were comparably low, although the 7-methyl group significantly slowed down the turnover rates of the polymerase when dCTP was incorporated. The stabilities of N7-methyl-9-deaza-dG and 7-methyl-7-deaza-dG against the actions of formamidopyrimidine DNA glycosylase (Fpg) and human alkyladenine DNA glycosylase (hAAG) were also examined. N7-methyl-9-deaza-dG was stable in the presence of both enzymes. In contrast, 7-methyl-7-deaza-dG was cleaved by Fpg, and possibly by hAAG but at an extremely slow rate. This study suggests that N7-alkyl-9-deaza-dG is a better analogue than 7-alkyl-7-deaza-dG for cellular studies.
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MEDLINE
Assunto principal:
Proteínas de Escherichia coli
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DNA Glicosilases
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Desoxiguanosina
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DNA Polimerase I
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article