Ekland E H, Bartel D P
Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA.
Nature. 1996 Jul 25;382(6589):373-6. doi: 10.1038/382373a0.
The hypothesis that certain RNA molecules may be able to catalyse RNA replication is central to current theories of the early evolution of life. In support of this idea, we describe here an RNA that synthesizes RNA using the same reaction as that employed by protein enzymes that catalyse RNA polymerization. In the presence of the appropriate template RNA and nucleoside triphosphates, the ribozyme extends an RNA primer by successive addition of up to six mononucleotides. The added nucleotides are joined to the growing RNA chain by 3',5'-phosphodiester linkages. The ribozyme shows marked template fidelity: extension by nucleotides complementary to the template is up to 1,000 times more efficient than is extension by mismatched nucleotides.
某些RNA分子或许能够催化RNA复制，这一假说乃是当前生命早期进化理论的核心内容。为支持这一观点，我们在此描述一种RNA，它利用与催化RNA聚合反应的蛋白质酶相同的反应来合成RNA。在合适的模板RNA和核苷三磷酸存在的情况下，该核酶通过连续添加多达六个单核苷酸来延伸RNA引物。添加的核苷酸通过3'，5'-磷酸二酯键连接到不断增长的RNA链上。该核酶表现出显著的模板保真度：与模板互补的核苷酸进行的延伸效率比错配核苷酸进行的延伸效率高出多达1000倍。
