Sequence-specific DNA primer effects on telomerase polymerization activity
Sequence-specific DNA primer effects on telomerase polymerization activity
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DOI：
10.1128/mcb.13.10.6586-6599.1993
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发表时间：
1993-10
影响因子：
5.3
通讯作者：
M. Lee;E. Blackburn
中科院分区：
文献类型：
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作者：
M. Lee;E. Blackburn
核糖核蛋白酶端粒酶通过复制酶的RNA部分内的模板序列来合成端粒DNA的一条链。通过对聚合反应动力学的研究，分析了嗜热四膜虫端粒酶的作用机理和性质。该酶通过延长DNA引物合成TTGGGG重复序列，即该物种的端粒DNA序列，所述DNA引物的3'端碱基与RNA的模板形成结构域配对。该酶被发现与短（10至12个核苷酸）引物的作用nonprocessive，但成为进行性TTGGGG重复被添加。具有共同3'末端的短引物的5'序列的变化鉴定了序列特异性效应，这些效应与涉及引物3'末端与RNA模板的碱基配对的效应不同，并且可以通过增加催化率显着诱导酶活性。端粒酶聚合反应。这些结果确定了一个额外的机制基础端粒和DNA末端识别端粒酶在体内。
The ribonucleoprotein enzyme telomerase synthesizes one strand of telomeric DNA by copying a template sequence within the RNA moiety of the enzyme. Kinetic studies of this polymerization reaction were used to analyze the mechanism and properties of the telomerase from Tetrahymena thermophila. This enzyme synthesizes TTGGGG repeats, the telomeric DNA sequence of this species, by elongating a DNA primer whose 3' end base pairs with the template-forming domain of the RNA. The enzyme was found to act nonprocessively with short (10- to 12-nucleotide) primers but to become processive as TTGGGG repeats were added. Variation of the 5' sequences of short primers with a common 3' end identified sequence-specific effects which are distinct from those involving base pairing of the 3' end of the primer with the RNA template and which can markedly induce enzyme activity by increasing the catalytic rate of the telomerase polymerization reaction. These results identify an additional mechanistic basis for telomere and DNA end recognition by telomerase in vivo.