Cloning and Expression of a New Site-Specific Methyltransferase M.SscL1I from Staphylococcus sp. L1

L. Yu. Vasiljeva¹, 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@vega.protres.ru

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 March 10, 1999; Revision received April 8, 1999

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The gene of the new site-specific methyltransferase M.SscL1I belonging to the same modification-restriction system as the previously described by us site-specific endonuclease SscL1I has been cloned from the natural strain Staphylococcus sp. L1. A plasmid to express the methylase gene under control of the T7 phage-specific promotor has been constructed. Conditions were found to express the recombinant methylase M.SscL1I and to purify it to near homogeneity. It is shown that the methylase modifies the adenine base in the recognition site 5´-GANTC-3´.

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KEY WORDS: adenine-specific methyltransferase, cloning, overproducing strain, Hinf I

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