[Substrate specificity and properties of methyl-directed site-specific dna endonucleases].

Methyl-directed site-specific DNA endonucleases (MD endonucleases) form a small group of enzymes which specifically cleave only methylated DNA. There are N6-methyladenine- and 5-methylcytosine-directed enzymes in this group. In spite of limited information on the MD endonucleases they are considered to be a very interesting subject for both fundamental investigations and practical use in biotechnology and epigenomics.

[Recombinant DNA-methyltransferase M1.Bst19I from Bacillus stearothermophilus 19: purification, propeties and amino acids sequence analysis].

The M1.Bst19I DNA-methyltransferase gene from restriction-modification system Bst19I (recognition sequence 5'-GCATC-3') in Bacillus stearothermophilus 19 has been cloned in the expressing vector pJW, that carries a tandem of thermo inducible promoters P(R)/P(L) from phage lambda. Highly purified enzyme has been isolated by chromatography on various resins from E.