Zaug A J, Grabowski P J, Cech T R
Nature. 1983;301(5901):578-83. doi: 10.1038/301578a0.
The intervening sequence (IVS) of the Tetrahymena ribosomal RNA precursor is excised as a linear RNA molecule which subsequently cyclizes itself in a protein-independent reaction. Cyclization involves cleavage of the linear IVS RNA 15 nucleotides from its 5' end and formation of a phosphodiester bond between the new 5' phosphate and the original 3'-hydroxyl terminus of the IVS. This recombination mechanism is analogous to that by which splicing of the precursor RNA is achieved. The circular molecules appear to have no direct function in RNA splicing, and we propose the cyclization serves to prevent unwanted RNA from driving the splicing reactions backwards.
嗜热四膜虫核糖体RNA前体的居间序列（IVS）作为线性RNA分子被切除，随后在一个不依赖蛋白质的反应中自身环化。环化涉及从线性IVS RNA的5'端切割15个核苷酸，并在新的5'磷酸和IVS原来的3'-羟基末端之间形成磷酸二酯键。这种重组机制类似于前体RNA剪接的实现方式。环状分子似乎在RNA剪接中没有直接功能，我们提出环化作用是为了防止不需要的RNA使剪接反应逆向进行。
