Digestion of highly modified bacteriophage DNA by restriction endonucleases

作者： Lan-Hsiang Huang , Chris M. Farnet , Kenneth C. Ehrlich , Melanie Ehrlich

关键词: DNA polymerase 、 DNA polymerase II 、 Molecular biology 、 Biochemistry 、 DNA 、 Endonuclease 、 Base pair 、 DNA ligase 、 Flap endonuclease 、 DNA clamp 、 Biology

摘要: The ability of thirty Type II restriction endonucleases to cleave five different types highly modified DNA has been examined. substrates were derived from relatively large bacteriophage genomes which contain all or most the cytosine thymine residues substituted at 5-position. These substituents a proton (PBS1 DNA), hydroxymethyl group (SP01 methyl (XP12 glucosylated (T4 phosphoglucuronated, 4,5-dihydroxypentyl (SP15 DNA). Although PBS1 and SP01 digested by enzymes, they cleaved much more slowly than was normal many them. 5-Methylcytosine-rich XP12 multiply T4 SP15 DNAs resistant these endonucleases. only enzyme that TaqI, fragmented them extensively.