Isolation and some properties of the site‐specific endonuclease and methylase Bme216I from Bacillus megaterium 216

• Published in: European journal of biochemistry Vol. 165; no. 3; pp. 565 - 570
• Main Authors: MATVIENKO, Nicholas I., KRAMAROV, Vladimir M., PACHKUNOV, Dmitrii M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.1987; Blackwell
• Subjects: Applied sciences; Exact sciences and technology; Other techniques and industries
• ISSN: 0014-2956; 1432-1033
• DOI: 10.1111/j.1432-1033.1987.tb11477.x

The site‐specific endonuclease Bme216I was isolated as a homogeneous preparation by chromatography on phosphocellulose, hydroxyapatite and heparin‐agarose. The molecular mass of the enzyme, determined by gel filtration and by electrophoresis under denaturing conditions, was found to be 60 kDa and 30 kDa respectively. These data indicate that the native enzyme consists of two identical subunits. The enzyme recognized the pentanucleotide sequence and cleaves the sequence as indicated by arrows. The optimal concentration for endonuclease reaction is 6–7 mM Mg2+. The endonuclease relaxes its specificity in the presence of glycerol or dimethyl sulfoxide at low Mg2+ concentration (1–3 mM). Methylase Bme216I, which protects DNA against endonuclease Bme216I action by DNA methylation, was isolated from the same bacterial strain.