The activity of eukaryotic DNA methyltransferase diminishes with time when the enzyme is incubated with high concentrations (200-300 micrograms/ml) of unmethylated double-stranded Micrococcus luteus DNA. Under similar conditions, single-stranded DNA induces only a limited decrease of enzyme activity. The inactivation process is apparently due to a slowly progressive interaction of the enzyme with double-stranded DNA that is independent of the presence of S-adenosyl-L-methionine. The inhibited enzyme cannot be reactivated either by high salt dissociation of the DNA-enzyme complex or by extensive digestion of the DNA. Among synthetic polydeoxyribonucleotides both poly(dG-dC).poly(dG-dC) and poly(dA-dT).poly(dA-dT), but not poly(dI-dC).poly(dI-dC), cause inactivation of DNA methyltransferase. This inactivation process may be of interest in regulating the 'de novo' activity of the enzyme.
Inactivation of de novo DNA methyltransferase activity by high concentrations of double-stranded DNA / Palitti, Franco; Carotti, Daniela; Gruenwald, S; Rispoli, M; Whitehead, Ep; Salerno, Costantino; Strom, Roberto; Drahovsky, D.. - In: BIOCHIMICA ET BIOPHYSICA ACTA. - ISSN 0006-3002. - STAMPA. - 910:3(1987), pp. 292-296. [10.1016/0167-4781(87)90122-9]
Inactivation of de novo DNA methyltransferase activity by high concentrations of double-stranded DNA.
PALITTI, Franco;CAROTTI, Daniela;SALERNO, Costantino;STROM, Roberto;
1987
Abstract
The activity of eukaryotic DNA methyltransferase diminishes with time when the enzyme is incubated with high concentrations (200-300 micrograms/ml) of unmethylated double-stranded Micrococcus luteus DNA. Under similar conditions, single-stranded DNA induces only a limited decrease of enzyme activity. The inactivation process is apparently due to a slowly progressive interaction of the enzyme with double-stranded DNA that is independent of the presence of S-adenosyl-L-methionine. The inhibited enzyme cannot be reactivated either by high salt dissociation of the DNA-enzyme complex or by extensive digestion of the DNA. Among synthetic polydeoxyribonucleotides both poly(dG-dC).poly(dG-dC) and poly(dA-dT).poly(dA-dT), but not poly(dI-dC).poly(dI-dC), cause inactivation of DNA methyltransferase. This inactivation process may be of interest in regulating the 'de novo' activity of the enzyme.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
