Ikawa Y, Naito D, Aono N, Shiraishi H, Inoue T
Department of Chemistry, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan.
Nucleic Acids Res. 1999 Apr 15;27(8):1859-65. doi: 10.1093/nar/27.8.1859.
Terminal tetraloops consisting of GNRA sequences are often found in biologically active large RNAs. The loops appear to contribute towards the organization of higher order RNA structures by forming specific tertiary interactions with their receptors. Group IC3 introns which possess a GAAA loop in the L2 region often have a phylogenetically conserved motif in their P8 domains. In this report, we show that this conserved motif stands as a new class of receptor that distinguishes the sequences of GNRA loops less stringently than previously known receptors. The motif can functionally substitute an 11 nt motif receptor in the Tetrahymena ribozyme. Its structural and functional similarity to one class of synthetic receptors obtained from in vitro selection is observed.
由GNRA序列组成的末端四环常常出现在具有生物活性的大RNA中。这些环似乎通过与其受体形成特定的三级相互作用，对高阶RNA结构的组织有所贡献。在L2区域具有GAAA环的I C3组内含子在其P8结构域中通常有一个系统发育保守基序。在本报告中，我们表明，这个保守基序代表了一类新的受体，它对GNRA环序列的区分比以前已知的受体更宽松。该基序在四膜虫核酶中可在功能上替代一个11个核苷酸的基序受体。观察到它与一类通过体外筛选获得的合成受体在结构和功能上的相似性。
