THE INTERVENING SEQUENCE RNA OF TETRAHYMENA IS AN ENZYME
THE INTERVENING SEQUENCE RNA OF TETRAHYMENA IS AN ENZYME
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DOI：
10.1126/science.3941911
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发表时间：
1986-01-31
期刊：
影响因子：
56.9
通讯作者：
CECH, TR
中科院分区：
文献类型：
--
作者：
ZAUG, AJ;CECH, TR
嗜热四膜虫自剪接核糖体RNA （rRNA）介入序列的缩短形式在体外作为酶。该酶以序列依赖的方式催化寡核苷酸底物的裂解和再连接，km = 42 μMandkcat= 2 min-1。该反应机制类似于rRNA前体自剪接。以五胱甘酸为底物，经过连续的裂解和再连接反应合成多胱甘酸。因此，RNA分子可以作为RNA聚合酶，与蛋白质酶的不同之处在于它使用内部而不是外部模板。atph9，同样的RNA酶具有序列特异性核糖核酸酶的活性。
A shortened form of the self-splicing ribosomal RNA (rRNA) intervening sequence ofTetrahymena thermophilaacts as an enzyme in vitro. The enzyme catalyzes the cleavage and rejoining of oligonucleotide substrates in a sequence-dependent manner withKm= 42 μMandkcat= 2 min-1. The reaction mechanism resembles that of rRNA precursor self-splicing. With pentacytidylic acid as the substrate, successive cleavage and rejoining reactions lead to the synthesis of polycytidylic acid. Thus, the RNA molecule can act as an RNA polymerase, differing from the protein enzyme in that it uses an internal rather than an external template. AtpH 9, the same RNA enzyme has activity as a sequence-specific ribonuclease.