Zaug A J, Been M D, Cech T R
Nature. 1986;324(6096):429-33. doi: 10.1038/324429a0.
A shortened form of the Tetrahymena self-splicing ribosomal RNA intervening sequence acts as an endoribonuclease, catalysing the cleavage of large RNA molecules by a mechanism involving guanosine transfer. The sequence specificity approaches that of the DNA restriction endonucleases. Site-specific mutagenesis of the enzyme active site alters the substrate sequence specificity in a predictable manner, so that endoribonucleases can be synthesized to cut at a variety of tetranucleotide sequences.
嗜热四膜虫自我剪接核糖体RNA间隔序列的一种缩短形式可作为一种核糖核酸内切酶，通过一种涉及鸟苷转移的机制催化大RNA分子的切割。其序列特异性接近DNA限制性内切酶的序列特异性。对该酶活性位点进行位点特异性诱变会以可预测的方式改变底物序列特异性，从而可以合成核糖核酸内切酶以切割各种四核苷酸序列。
