title: Action of single-strand specific nucleases on model DNA heteroduplexes of defined size and sequence.
abstract: The sensitivity of the model DNAs containing dA-dG and dtg-dG heteroduplex regions of defined length to S1 and mung bean single-strand specific nucleases was tested by polyacrylamide gel electrophoretic analysis of the distribution of product oligonucleotides. Single-base mismatch heteroduplexes were extremely resistant to these nucleases, although low levels of cleavage at the heteroduplex nucleotide were observed at high nuclease concentrations. The nuclease sensitivity of dA-dtg heteroduplex regions increased gradually as the length of the heteroduplex region increased frome one to six nucleotides. The sensitivity of dG-dG heteroduplexes three to five nucleotides long was considerably greater than that of the single dtg-dG mismatch.
mesh_terms: D004277:DNA, Single-Stranded; D003839:Deoxyadenosines / Q000031:analogs & derivatives / Q000378:metabolism; D003851:Deoxyribonucleases / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006150:Guanine Nucleotides / Q000378:metabolism; D066298:In Vitro Techniques; D011089:Polydeoxyribonucleotides / Q000378:metabolism*
chemical_list: D004277:DNA, Single-Stranded; D003839:Deoxyadenosines; D006150:Guanine Nucleotides; D011089:Polydeoxyribonucleotides; D003851:Deoxyribonucleases