Dimeric Structure of the Blue Light Sensor Protein Photozipper in the Active State
Dimeric Structure of the Blue Light Sensor Protein Photozipper in the Active State
复制标题
活性状态下蓝光传感器蛋白光电拉链的二聚体结构
DOI：
10.1021/acs.biochem.7b01045
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发表时间：
2017
期刊：
影响因子：
2.9
通讯作者：
Mino Hiroyuki
中科院分区：
文献类型：
--
作者：
Ozeki Kohei;Tsukuno Hiroyuki;Nagashima Hiroki;Hisatomi Osamu;Mino Hiroyuki
光氧电压敏感（LOV）结构域在植物和微生物的蓝光（BL）传感中起着至关重要的作用。LOV结构域通常与效应子结构域相关，并以BL依赖性方式调节效应子结构域的活性。光拉链（PZ）在黑暗状态下是单体。BL诱导PZ的可逆二聚化，随后增加其对靶DNA序列的亲和力。在这项研究中，我们报告的分析PZ的脉冲电子-电子双共振（PELDOR）。在LOV-C254 S（没有bZIP结构域）和PZ-C254 S突变体中存在二硫苏糖醇的情况下，通过BL照明形成中性黄素自由基，其中负责加合物形成的半胱氨酸残基被丝氨酸取代。在LOV-C254 S和PZ-C254 S中检测到中性自由基之间的3 MHz磁偶极相互作用，表明这些突变体在自由基状态下是二聚体。PELDOR模拟表明，自由基对之间的距离接近于从“轻态”中的二聚体晶体结构估计的距离[Heintz，U.，和Schlichting，I.（2016）eLife 5，e11860]，表明在自由基状态下，PZ-C254 S中的LOV结构域形成与缺少bZIP结构域的LOV-C254 S类似的二聚体。
The light oxygen voltage-sensing (LOV) domain plays a crucial role in blue light (BL) sensing in plants and microorganisms. LOV domains are usually associated with the effector domains and regulate the activities of effector domains in a BL-dependent manner. Photozipper (PZ) is monomeric in the dark state. BL induces reversible dimerization of PZ and subsequently increases its affinity for the target DNA sequence. In this study, we report the analyses of PZ by pulsed electron–electron double resonance (PELDOR). The neutral flavin radical was formed by BL illumination in the presence of dithiothreitol in the LOV-C254S (without the bZIP domain) and PZ-C254S mutants, where the cysteine residue responsible for adduct formation was replaced with serine. The magnetic dipole interactions of 3 MHz between the neutral radicals were detected in both LOV-C254S and PZ-C254S, indicating that these mutants are dimeric in the radical state. The PELDOR simulation showed that the distance between the radical pair is close to that estimated from the dimeric crystal structure in the “light state” [Heintz, U., and Schlichting, I. (2016)eLife5, e11860], suggesting that in the radical state, LOV domains in PZ-C254S form a dimer similar to that of LOV-C254S, which lacks the bZIP domain.