Open AccessCloning and expression of cDNA for rat O6-methylguanine-DNA methyltransferse
Author(s) -
Kunihiko Sakumi,
Akio Shiraishi,
Hiroshi Hayakawa,
Mutsuo Sekiguchi
Publication year - 1991
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/19.20.5597
Subject(s) - complementary dna , biology , microbiology and biotechnology , methyltransferase , dna methyltransferase , o 6 methylguanine dna methyltransferase , dna , peptide sequence , escherichia coli , cdna library , biochemistry , molecular cloning , gene , methylation
cDNA for O6-methylguanine-DNA methyltransferase was isolated by screening rat liver cDNA libraries, using as a probe the human cDNA sequence for methyltransferase. The rat cDNA encodes a protein with 209 amino acid residues. The predicted amino acid sequence of the rat methyltransferase exhibits considerable homology with those of the human, yeast and bacterial enzymes, especially around putative methyl acceptor sites. When the cDNA was placed under control of the lac promoter and expressed in methyltransferase-deficient Escherichia coli (ada-, ogt-) cells, a characteristic methyltransferase protein was produced. The rat DNA methyltransferase thus expressed could complement the biological defects of the E. coli cell caused by lack of its own DNA methyltransferases; e.g. increased sensitivity to alkylating agents in terms of both cell death and mutation induction.