Molecular basis of ferredoxin:NADP(+) reductase interactions with FNR binding domains from TROL and Tic62 proteins
Molecular basis of ferredoxin:NADP(+) reductase interactions with FNR binding domains from TROL and Tic62 proteins
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DOI：
10.1016/j.molstruc.2020.128281
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发表时间：
2020-09-05
影响因子：
3.8
通讯作者：
Bertosa, Branimir
中科院分区：
文献类型：
--
作者：
Kekic, Tadija;Fulgosi, Hrvoje;Bertosa, Branimir
铁氧还蛋白-NADP（+）氧化还原酶（FNR）催化铁氧还蛋白-NADP（+）的光合电子传递。FNR在叶绿体膜上的定位是通过类囊体硫氰酸酯样蛋白（TROL）的动态相互作用和与Tic 62蛋白的持久相互作用来实现的。在这种相互作用中，FNR在来自TROL或Tic 62蛋白的FNR相互作用结构域的存在下形成同源二聚体复合物。从FNR同二聚体复合物的晶体结构开始，对由FNR蛋白和/或来自TROL和Tic 62蛋白的FNR结合结构域在不同pH下组成的各种系统进行分子动力学模拟。模拟的结果使识别的最重要的区域的非共价相互作用的蛋白质和它们的详细映射。在硅片上的突变被引入和模拟，以研究其对蛋白质复合物的结构特性，动力学和稳定性的影响。FNR蛋白质之间的界面区域，主要由疏水相互作用组成，被确定并显示出受到ITEPs保守的脯氨酸和丝氨酸（PPSS区域）的强烈影响。五个功能上重要的氢键网络，跨越所涉及的蛋白质的主要结构元素进行了鉴定和表征。其中三个具有pH依赖性，可能作为pH调节开关的蛋白质复合物的构象变化。所提出的计算结果提供了强有力的基础TROL，Tic 62和FNR蛋白的体外实验，应该能够理解他们的行为在波动的环境条件。(C)2020 Elsevier B. V.版权所有。y
The final step of photosynthetic electron transfer from ferredoxin to NADP(+) is catalysed by ferredoxin: NADP(+) oxidoreductase (FNR). Localization of the FNR on the chloroplastic membrane is attained both, by the dynamic interaction via thylakoid rhodanese-like protein (TROL) and with the lasting interaction with the Tic62 protein. In such interactions, FNR forms a homodimeric complex in the presence of the FNR interacting domain from either TROL or Tic62 protein. Starting from crystal structure of FNR homodimeric complex, various systems consisting of the FNR proteins and/or the FNR binding domains from TROL and Tic62 proteins at the different pH were subjected to molecular dynamics simulations. Results of simulations enabled identification of the most important regions of non-covalent interactions between involved proteins and their detailed mapping. In silico mutations were introduced and simulated to investigate their influence to the structural properties, dynamics and stability of the protein complex. The interface regions between the FNR proteins, consisting mostly of hydrophobic interactions, were identified and shown to be under strong influence of the ITEPs conserved prolines and serines (PPSS region). Five functionally important hydrogen bond networks that span over the major structural elements of the involved proteins were identified and characterized. Three of them show pH dependence and might serve as the pH regulated switches for conformational changes of the protein complex. Presented computational results provide strong base for in vitro experiments on TROL, Tic62 and FNR proteins that should enable understanding of their behavior in the fluctuating environmental conditions. (C) 2020 Elsevier B.V. All rights reserved.y