Isolation and Characterization of Site-Specific Endonuclease Bsp123 I from Thermophilic Strain Bacillus species 123

D. V. Alzhanova¹, D. T. Alzhanov¹, L. A. Zheleznaya², and N. I. Matvienko^1*

¹Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142292 Russia; fax: (095) 924-0493; E-mail: nikmatv@sun.ipr.serpukhov.su

²Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142292 Russia; fax: (095) 135-6219.

^* To whom correspondence should be addressed.

Received August 12, 1997; Revision received October 8, 1997

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The preparation of site-specific endonuclease Bsp123 I was isolated and purified from the thermophilic strain Bacillus species 123. Endonuclease Bsp123 I recognizes the sequence CGCG and cleaves it in the middle between nucleotides G and C, producing blunt ends. Thus, Bsp123 I is an isoschizomer of FnuDII. The maximal activity of the enzyme is displayed at 42°C, pH 8.0, 100 mM NaCl, 10 mM MgCl₂.

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KEY WORDS: site-specific endonuclease, isoschizomer of FnuDII

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