Cleavage at the twelve-base-pair sequence 5'-TCTAGATCTAGA-3' using M.Xbal (TCTAGm6A) methylation and DpnI (Gm6A/TC) cleavage.
The DNA methylase M.Xbal was isolated from an E. coli recombinant clone. We deduce that the enzyme methylates at the sequence 5'-TCTAGm6A-3'. In combination with the methylation-dependent restriction endonuclease, DpnI (5'-Gm6A/TC-3'), DNA cleavage occurs at the sequence 5'-TCTAGA/TCTAGA-3'. This twelve-base-pair site should occur once every 16,000,000 base pairs in a random sequence of DNA. The exceptional rarity of the M.XbaI/DpnI sequence makes it an ideal candidate for transpositional integration of a unique cleavage site into bacterial genomes. Retrotransposition into mammalian genomes is also an attractive possibility.
Patel
Y
Y
California Institute of Biological Research, La Jolla 92037.
Van Cott
E
E
Wilson
G G
GG
McClelland
M
M
D000260:Adenoviruses, Human / Q000235:genetics; D010582:Bacteriophage lambda / Q000235:genetics; D001483:Base Sequence; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D008745:Methylation; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D015183:Restriction Mapping; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000378:metabolism*; D013379:Substrate Specificity
D004279:DNA, Viral; D009838:Oligodeoxyribonucleotides; C059639:DNA modification methylase XbaI; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D004262:DNA Restriction Enzymes; C020102:endodeoxyribonuclease DpnI; D015252:Deoxyribonucleases, Type II Site-Specific