A Site-Specific Endonuclease BspR7I from Thermophilic Strain Bacillus sp. R7

L. Yu. Vasiljeva,¹ L. A. Zheleznaya,² and N. I. Matvienko^1,3

¹Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142292 Russia; fax: (7-095) 924-04-93; E-mail: protres@sovam.com

²Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, 142292 Russia; fax: (7-095) 135-62-19.

³To whom correspondence should be addressed.

Submitted June 18, 1996; revision submitted July 9, 1996.

A site-specific endonuclease BspR7I preparation has been isolated and purified to homogeneity from the thermophilic strain Bacillus sp. R7. DNA cleavage proceeds according to the scheme 5'-CC***TNAGG-3' 3'-GGANT***CC-5' and thus the enzyme belongs to the second class of restriction endonucleases and is an isoschizomer of Bsu36I. The isolated protein has a molecular mass of 37 kD and is present in solution in the form of a monomer. BspR7I is active over a wide range of temperatures, from 37 to 48°C. The enzyme is relatively stable.

KEY WORDS: site-specific endonuclease, Bsu36I isoschizomer.

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