CLONING AND NUCLEOTIDE-SEQUENCE OF APALI RESTRICTION-MODIFICATION SYSTEM FROM ACETOBACTER-PASTEURIANUS IFO-13753

The ApaLI restriction-modification system from Acetobacter pasteurianu s IFO 13753 recognizes the nucleotide sequence GTGCAC, The gene coding for the ApaLI methylase (M.ApaLI) was cloned into Escherichia coli DH 5 alpha MCR, and the nucleotide sequence of the gene was analyzed, The M.ApaLI gene coded for a protein of 429 amino acid residues (molecula r mass, 46,554 daltons), The ApaLI restriction endonuclease (R.ApaLI) gene was analyzed by inverse polymerase chain reaction, The R.ApaLI ge ne coded for a protein of 375 amino acid residues (molecular mass, 42, 143 daltons), The two genes had the same orientation separated by two base pairs. The deduced amino acid sequence of M.ApaLI shows significa nt similarities to the family of cytosine-5 methylases, However, the d educed amino acid sequence of R.ApaLI did not have as much relatedness in the nucleotide sequence, when compared with those of the other res triction endonucleases already reported.