Detection of a CpA methylase in an insect system: characterization and substrate specificity
- 24 Downloads
A cytosine-specific DNA methyltransferase (EC 18.104.22.168) has been purified to near homogeneity from a mealybug (Planococcus lilacinus). The enzyme can methylate cytosine residues in CpG sequences as well as CpA sequences. The apparent molecular weight of the enzyme was estimated as 135,000 daltons by FPLC. The enzyme exhibits a processive mode of action and a salt dependance similar to mammalian methylases. Mealybug methylase exhibits a preference for denatured DNA substrates.
Key wordsDNA methylation coccids processive enzyme RNA inhibition CpI methylation
Unable to display preview. Download preview PDF.
- 1.Riggs AD: X inactivation, differentiation and DNA methylation. Cyto Genet Cell Genet 14: 9–25, 1975Google Scholar
- 2.Razin A, Friedman J: DNA methylation and its possible biological roles. Prog Nucleic Acids Res Mol Biol 25: 33–52, 1981Google Scholar
- 5.Adams RLP, Davis T, Fulton J, Kirk O, Qureshi M: Eukaryotic DNA methylase-properties and action on native DNA and chromatin. Curr Top Microbiol & Immunol 108: 143–156, 1984Google Scholar
- 8.Deobagkar DN, Muralidharan K, Devare SG, Kalghatgi KK, Chandra HS: The mealybug chromosome system I: Unusual methylated bases and dinucleotides in DNA of aPlanococcus species. J Biosci 4: 513–526, 1982Google Scholar
- 10.Brown SW, Chandra HS: Chromosome imprinting and the differential regulation of homologous chromosome. In: L. Goldstein, DM Prescott (eds.) Cell Biology: A comprehensive Treatise, Vol. I Genetic Mechanisms of cells, Academic Press, New York, 109–189, 1977Google Scholar
- 16.Roy PW, Weissenbach A: DNA methylase from HeLa cell nuclei. Nucl Acids Res 2: 1169–1684, 1975Google Scholar
- 17.Pfeifer GP, Grunwald S, Boehm TLJ, Drohovsky D: Isolation and characterization of DNA cytosine 5-methyl transferase from human placenta. Biochim Biophys Acta 140: 323–330, 1983Google Scholar
- 32.Turnball JF, Adams RLP: DNA methylase: purification from ascites cells and the effect of various DNA substrates on its activity. Nucl Acids Res 3: 677–695, 1976Google Scholar