title: The 5'-cytosine in CCGG1 is methylated in two eukaryotic DNAs and Msp I is sensitive to methylation at this site.
abstract: Novikoff rat hepatoma and bovine liver DNAs were digested with Msp I or Hpa II. Restriction fragments were end-labeled using [alpha-32P]-dCTP and the Klenow fragment of E. coli DNA polymerase I and then digested to 2'-deoxyribonucleoside-3'-monophosphates using micrococcal nuclease and spleen phosphodiesterase. Mononucleotides were separated by two-dimensional thin layer chromatography, localized by radioautography, and the [32P]-label quantitated by scintillation spectrometry. This method, based on known specificities of Msp I and Hpa II, shows that CCGG, CMGG, and MCGG (M refers to 5-methylcytosine) occur at frequencies of 89.6%, 1.4%, and 9.0%, respectively, in the rat DNA and at 41.6%, 48.3%, and 10.0%, respectively, in the bovine DNA. [32P] recovery in 3'-5-MedCMP from end-labeled Msp I digests was negligible compared to recovery from Hpa II digests. Hence, Msp I is sensitive to methylation at the 5' cytosine in the sequence CCGG.
mesh_terms: D044503:5-Methylcytosine; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D003596:Cytosine / Q000031:analogs & derivatives* / Q000032:analysis; D004247:DNA; D004262:DNA Restriction Enzymes; D004273:DNA, Neoplasm; D003851:Deoxyribonucleases; D008099:Liver / Q000032:analysis*; D008114:Liver Neoplasms, Experimental / Q000032:analysis*; D009838:Oligodeoxyribonucleotides / Q000032:analysis*; D009841:Oligonucleotides / Q000032:analysis*; D051381:Rats
chemical_list: D004273:DNA, Neoplasm; D009838:Oligodeoxyribonucleotides; D009841:Oligonucleotides; D044503:5-Methylcytosine; D003596:Cytosine; D004247:DNA; D003851:Deoxyribonucleases; D004262:DNA Restriction Enzymes