Determination of a Non-methylated Deoxycytidine Residue in the Recognition Site of DNA-methyltransferases

E. A. Kubareva^1*, J. Walter², O. V. Vorob'eva¹, M. V. Razumikhin³, A. S. Karyagina³, P. C. K. Lau⁴, and T. Trautner²

¹Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 939-3181; E-mail: kubareva@genebee.msu.su

²Max-Planck-Institut für Moleculare Genetic, Ihnestrasse 73, Berlin D-14195, Germany; fax: (49) 30-8413-1382; E-mail: j.walter@mx.uni-saarland.de

³Institute of Agricultural Biotechnology, Timiryazevskaya ul. 42, Moscow, 127550 Russia; fax: (095) 977-0947; E-mail: anna@jab.ac.ru

⁴Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec H4P 2R2, Canada; fax: (1-514) 496-6265; E-mail: Peter.Lau@nrc.ca

^* To whom correspondence should be addressed.

Received June 8, 2001

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A method for determination of a non-methylated deoxycytidine (dC) residue in the recognition site of 5-cytosine DNA-methyltransferases is suggested. The method is based on treatment of methylated DNA by sodium bisulfite and successive reaction of the thus modified DNA with a repair enzyme, uracil-DNA glycosylase. This method was successfully applied to identify NlaX methyltransferase specificity.

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KEY WORDS: 5-cytosine DNA-methyltransferase, non-methylated and methylated bases, bisulfite reaction, uracil-DNA glycosylase

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