作者: S. Agrawal , S. H. Mayrand , P. C. Zamecnik , T. Pederson
关键词:
摘要: Oligodeoxynucleotides containing phosphodiester or modified internucleoside linkages were investigated with respect to their ability be acted on by ribonuclease H activities present in a HeLa cell nuclear extract after hybridization complementary sequences RNA. nucleotides 2-14 of human U1 small RNA investigated. Extensive cleavage was observed the unmodified oligodeoxynucleotide and phosphorothioate analogue but not U1-complementary oligodeoxynucleotides methylphosphonate, phosphoro-N-morpholidate, phosphoro-N-butylamidate linkages. Additional experiments using 514-nucleotide-long substrate demonstrated capacity phosphodiester- phosphorothioate-linked (but ones linkages) serve as RNase targets when hybridized an internal site. Detailed comparisons revealed phosphodiester-linked more efficient than comparable oligomers action. Various pentadecamer test 2-6 consecutive flanked H-resistant methylphosphonate afforded precise "site-directed" excision within DNA.RNA hybrid. These results assort oligodeoxynucleotide-containing hybrids into H-sensitive -resistant classes also provide clues how makes contact DNA strand