Three-dimensional structure of the Tn5 synaptic complex transposition intermediate
Three-dimensional structure of the Tn5 synaptic complex transposition intermediate
复制标题
DOI：
10.1126/science.289.5476.77
复制
发表时间：
2000-07-07
期刊：
影响因子：
56.9
通讯作者：
Rayment, I
中科院分区：
文献类型：
--
作者：
Davies, DR;Goryshin, IY;Rayment, I
基因组进化受到DNA转座的深刻影响，DNA转座是一种定义的DNA片段在基因组中自由移动的过程。转座是由转座酶介导的，类似的事件也是由逆转录病毒整合酶如人类免疫缺陷病毒1(HIV-1)整合酶催化的，了解这些蛋白质如何与DNA相互作用是理解转座的分子基础的关键。我们报道了原核生物Tn5转座酶与Tn5转座子末端DNA的复合体的三维结构，其分辨率为2.3埃。分子组装是二聚体的，每个双链DNA分子都被两个蛋白质亚基结合，将转座子末端定向到活性部位。这种结构为理解转座的许多方面提供了分子框架，包括转座子末端DNA被一个亚基结合和第二个亚基切割，两条DNA链通过一个发夹中间体被一个活性部位切割，以及链转移到靶DNA。
Genomic evolution has been profoundly influenced by DNA transposition, a process whereby defined DNA segments move freely about the genome. Transposition is mediated by transposases, and similar events are catalyzed by retroviral integrases such as human immunodeficiency virus-1 (HIV-1) integrase, Understanding how these proteins interact with DNA is central to understanding the molecular basis of transposition. We report the three-dimensional structure of prokaryotic Tn5 transposase complexed with Tn5 transposon end DNA determined to 2.3 angstrom resolution. The molecular assembly is dimeric, where each double-stranded DNA molecule is bound by both protein subunits, orienting the transposon ends into the active sites. This structure provides a molecular framework for understanding many aspects of transposition, including the binding of transposon end DNA by one subunit and cleavage by a second, cleavage of two strands of DNA by a single active site via a hairpin intermediate, and strand transfer into target DNA.