Lamm G M, Blencowe B J, Sproat B S, Iribarren A M, Ryder U, Lamond A I
EMBL, Heidelberg, FRG.
Nucleic Acids Res. 1991 Jun 25;19(12):3193-8. doi: 10.1093/nar/19.12.3193.
RNA duplexes containing the modified base 2-amino-adenine in place of adenine are stabilized through the formation of three hydrogen bonds in 2-amino A.U base pairs. Antisense 2'-O-alkyloligoribonucleotide probes incorporating 2-aminoadenosine are thus able to efficiently affinity select RNP particles which are otherwise inaccessible. This has allowed the efficient and specific depletion of U5 snRNP from HeLa cell nuclear splicing extracts. U5 snRNP is shown to be essential for spliceosome assembly and for both steps of pre-mRNA splicing. The absence of U5 snRNP prevents the stable association of U4/U6 but not U1 and U2 snRNPs with pre-mRNA.
含有修饰碱基2-氨基腺嘌呤而非腺嘌呤的RNA双链体通过在2-氨基A·U碱基对中形成三个氢键而得以稳定。因此，掺入2-氨基腺苷的反义2'-O-烷基寡核糖核苷酸探针能够有效地亲和选择原本无法接近的RNP颗粒。这使得从HeLa细胞核剪接提取物中有效且特异性地耗尽U5 snRNP成为可能。研究表明，U5 snRNP对于剪接体组装以及前体mRNA剪接的两个步骤均至关重要。U5 snRNP的缺失会阻止U4/U6而非U1和U2 snRNP与前体mRNA的稳定结合。
