title: Specific fragmentation of T7 phage DNA at low-melting sites.
abstract: A method has been developed for selective fragmentation of T7 DNA at AT-rich regions. The molecules have been subjected to complete digestion with single-strand-specific SI endonuclease after fixation of DNA AT-rich regions in the denatured state by glyoxal. The treatment resulted in three fragments having molecular weights of 13.6 +/- 0.4, 8.2 +/- 0.4 and 3.5 +/- 0.16 megadaltons as determined by electron microscopy. The position of these fragments along the T7 DNA molecule has been determined by means of analysis of the intermediates during SI-cleavage.
mesh_terms: D001483:Base Sequence; D003090:Coliphages / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism; D004720:Endonucleases / Q000378:metabolism; D006358:Hot Temperature; D008970:Molecular Weight; D009691:Nucleic Acid Denaturation
chemical_list: D004277:DNA, Single-Stranded; D004279:DNA, Viral; D004720:Endonucleases