Intracellular transcription of G-rich DNAs induces formation of G-loops, novel structures containing G4 DNA
Intracellular transcription of G-rich DNAs induces formation of G-loops, novel structures containing G4 DNA
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DOI：
10.1101/gad.1200804
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发表时间：
2004-07-01
影响因子：
10.5
通讯作者：
Maizels, N
中科院分区：
文献类型：
--
作者：
Duquette, ML;Handa, P;Maizels, N
我们发现，细胞内转录的G-丰富的区域产生新的DNA结构，可见的电子显微镜大（150-500 bp）的循环。这些G环是共转录形成的，它们在一条链上含有G4 DNA，在另一条链上含有稳定的RNA/DNA杂合体。G环的形成需要一个G丰富的非模板链，并反映了rG/dC碱基对的不寻常的稳定性。G-环和G4 DNA在体外或大肠杆菌中转录的质粒基因组内有效地形成。这些结果表明，G4 DNA可以在体内形成，这一发现对所有富含G的基因组区域的稳定性和维持都有影响。
We show that intracellular transcription of G-rich regions produces novel DNA structures, visible by electron microscopy as large (150-500 bp) loops. These G-loops are formed cotranscriptionally, and they contain G4 DNA on one strand and a stable RNA/DNA hybrid on the other. G-loop formation requires a G-rich nontemplate strand and reflects the unusual stability of the rG/dC base pair. G-loops and G4 DNA form efficiently within plasmid genomes transcribed in vitro or in Escherichia coli. These results establish that G4 DNA can form in vivo, a finding with implications for stability and maintenance of all G-rich genomic regions.