Internal Motions of Basic Side Chains of the Antennapedia Homeodomain in the Free and DNA-Bound States
Internal Motions of Basic Side Chains of the Antennapedia Homeodomain in the Free and DNA-Bound States
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DOI：
10.1021/acs.biochem.7b00885
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发表时间：
2017-11-07
期刊：
影响因子：
2.9
通讯作者：
Iwahara, Junji
中科院分区：
文献类型：
--
作者：
Dan Nguyen;Hoffpauir, Zoe A.;Iwahara, Junji
碱性侧链在蛋白质-DNA相互作用中起着至关重要的作用。在这项研究中，使用NMR光谱，我们研究了在自由状态下，并在与目标DNA的复合物中的果蝇果蝇触角同源结构域的精氨酸和赖氨酸侧链的动力学。我们测量了N-15弛豫的精氨酸和赖氨酸侧链在两个磁场，从其中确定的阳离子基团的广义序参数。与DNA小沟中的胸腺嘧啶碱基形成氢键的R5侧链的移动性大大减弱。发现与DNA磷酸盐形成分子间离子对的几个Lys和Arg侧链保留高迁移率，其序参数为
Basic side chains play crucial roles in protein-DNA interactions. In this study, using NMR spectroscopy, we investigated the dynamics of Arg and Lys side chains of the fruit fly Antennapedia homeodomain in the free state and in the complex with target DNA We measured N-15 relaxation for Arg and Lys side chains at two magnetic fields, from which generalized order parameters for the cationic groups were determined. Mobility of the R5 side chain, which makes hydrogen bonds with a thymine base in the DNA minor groove, was greatly dampened. Several Lys and Arg side chains that form intermolecular ion pairs with DNA phosphates were found to retain high mobility with the order parameter being