title: Methylation sensitivity of the restriction enzymes FnuDII and AccII.
abstract: The restriction enzymes FnuDII and AccII are isoschizomers of the DNA sequence 5'-CGCG-3'. We have determined that 5-methylcytidine at either cytidine position in this recognition sequence inhibits DNA cleavage by FnuDII and AccII. A third isoschizomer, ThaI was previously shown to exhibit an identical methylation sensitivity. It is remarkable that 3 restriction enzymes derived from diverse microbiological sources exhibit this identical methylation sensitivity.
mesh_terms: D003562:Cytidine / Q000031:analogs & derivatives / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D004262:DNA Restriction Enzymes / Q000378:metabolism*; D015257:DNA-Cytosine Methylases; D015252:Deoxyribonucleases, Type II Site-Specific; D008745:Methylation
chemical_list: D003562:Cytidine; C037664:DNA modification methylase HhaI; D015257:DNA-Cytosine Methylases; D004248:DNA (Cytosine-5-)-Methyltransferases; D004262:DNA Restriction Enzymes; C039566:CGCG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific; C016568:5-methylcytidine