Elucidating a DNA recognition mechanism of a transcriptional factor protein by characterizing dynamic processes of specific/non-specific DNA-bound complexes

转录因子sox 2是诱导性多能干细胞（induced pluripotent stem cell，iPSC）技术的主要基因之一。Sox 2具有高迁移率族盒（HMG）结构域，其仅特异性结合6-7 bp的DNA以发挥其功能。然而，sox 2的DNA识别机制还不完全清楚。在这项研究中，为了阐明sox 2如何识别靶序列，我们使用NMR研究了DNA结合后HMG结构域的动力学。我们发现，HMG结构域是灵活的，几乎在DNA的情况下展开。然而，当HMG结构域与靶序列结合时，HMG结构域与DNA形成稳定的结构。该研究表明，HMG结构域的未折叠结构在DNA结合后是稳定的。

Transcriptional factor sox2 is a one of the major factor gene used for induced pluripotent stem cell (iPSC) technologies. Sox2 possesses a high-mobility group box (HMG) domain, which specifically binds to only 6-7 bp of DNA to exert its function. However, DNA recognition mechanism of sox2 is not fully understood. In this study, to elucidate how sox2 recognizes the target sequence, we investigated dynamics of the HMG domain upon DNA binding using NMR. We found that the HMG domain is flexible and almost unfolded in the absence of DNA. However, when the HMG domain binds to the target sequences, the HMG domain forms stable structure with DNA. This study revealed that the unfolded structure of the HMG domain is stabilized upon DNA binding.