R.PabI is a restriction DNA glycosylase that recognizes the sequence 5'-GTAC-3' and hydrolyses the N-glycosidic bond of adenine in the recognition sequence. R.PabI drastically bends and unwinds the recognition sequence of double-stranded DNA (dsDNA) and flips the adenine and guanine bases in the recognition sequence into the catalytic and recognition sites on the protein surface. In this study, we determined the crystal structure of the R.PabI-dsDNA complex in which the dsDNA is drastically bent by the binding of R.PabI but the base pairs are not unwound. This structure is predicted to be important for the indirect readout of the recognition sequence by R.PabI. In the complex structure, wedge loops of the R.PabI dimer are inserted into the minor groove of dsDNA to stabilize the deformed dsDNA structure. A base stacking is distorted between the two wedge-inserted regions. R.PabI is predicted to utilize the distorted base stacking for the detection of the recognition sequence.

中文翻译：

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限制性DNA糖基化酶R.PabI的结合使双链DNA结构变形。

R.PabI是限制性DNA糖基化酶，其识别序列5'-GTAC-3'并水解识别序列中腺嘌呤的N-糖苷键。R.PabI极大地弯曲和展开双链DNA（dsDNA）的识别序列，并将识别序列中的腺嘌呤和鸟嘌呤碱基翻转到蛋白质表面的催化位点和识别位点。在这项研究中，我们确定了R.PabI-dsDNA复合物的晶体结构，其中dsDNA通过R.PabI的结合而急剧弯曲，但碱基对并未解链。预测该结构对于R.PabI间接读出识别序列很重要。在复杂的结构中，R.PabI二聚体的楔形环插入dsDNA的小槽中，以稳定变形的dsDNA结构。两个楔形插入区域之间的基础堆叠变形。预计R.PabI将利用扭曲的碱基堆积来检测识别序列。