A DNA METALLOENZYME WITH DNA-LIGASE ACTIVITY
A DNA METALLOENZYME WITH DNA-LIGASE ACTIVITY
复制标题
DOI：
10.1038/375611a0
复制
发表时间：
1995-06-15
期刊：
影响因子：
64.8
通讯作者：
SZOSTAK, JW
中科院分区：
文献类型：
--
作者：
CUENOUD, B;SZOSTAK, JW
单链DNA可以折叠成明确的序列依赖三级结构，特异性结合各种靶分子（1-10），这提高了一些折叠的单链DNA可能表现出类似于核酶和蛋白酶的催化活性的可能性。含有大部分脱氧核糖核苷酸的锤头核酶衍生物保留了切割RNA的能力（11），并且通过将锤头核酶的所有必需核糖核苷酸留在RNA“底物”上而生成“脱氧核酶”（12）。最近，体外选择已被用于分离显示Pb2+依赖性rna切割活性的DNA序列（13）。在这里，我们报告了通过体外选择（14-17）分离出一个小的单链DNA，这是一个Zn2+/Cu2+依赖的金属酶。该酶通过一个低聚脱氧核苷酸的5′-羟基和一个3′-磷咪唑烷在另一个低聚脱氧核苷酸上缩合，催化形成一个新的磷酸二酯键，并表现多重翻转连接。
SINGLE-STRANDED DNA can fold into well-defined sequence-dependent tertiary structures that specifically bind a variety of target molecules(1-10), raising the possibility that some folded single-stranded DNAs might exhibit catalytic activities similar to those of ribozymes and protein enzymes. Derivatives of the hammerhead ribozyme that contain a majority of deoxyribonucleotides retain the ability to cleave RNA(11), and a 'deoxyribozyme' was generated by leaving all essential ribonucleotides of the hammerhead on the RNA 'substrate'(12). Recently in vitro selection has been used to isolate a DNA sequence that shows Pb2+-dependent RNA-cleaving activity(13). Here we report the isolation by in vitro selection(14-17) of a small single-stranded DNA that is a Zn2+/Cu2+-dependent metalloenzyme. The enzyme catalyses the formation of a new phosphodiester bond by the condensation of the 5'-hydroxyl of one oligodeoxynucleotide and a 3'-phosphorimidazolide on another oligodeoxynucleotide, and shows multiple turnover ligation.