MOLECULAR MECHANISM OF REDOX REGULATION OF CHLOROPLAST ATP SYNTHSAE

在本项目中，我们打算从分子水平上了解叶绿体ATP合酶的氧化还原调控。在这三年的研究中，我们获得了以下几项重要发现：将氧化还原敏感叶绿体F1的γ亚基开关区引入细菌F1，揭示了旋转的氧化还原开关。我们发现，被氧化的Fl的酶活性被抑制的特征是在旋转行为中更频繁地出现长时间的停顿。b .利用膜整合嵌合复合物研究了叶绿体ATP合成酶的γ和ε亚基的调节功能。我们得出结论，这些亚基之间的相互作用对于γ亚基对FoF1复合物的氧化还原调控是重要的，并且这些调节亚基与酶的催化核心之间必须具有一定的结构匹配才能赋予细菌FoF1. c的氧化还原调控机制。基于三维结构分析的结果表明，菌株Fl对叶绿体F1的特异性抑制肽tentoxin具有敏感性。然后研究了该抑制剂存在下突变体Fl的旋转。揭示了抑制剂引起的停顿的变化。

In this project, we intended to understand the redox regulation of chloroplast ATP synthase at the molecular level. For these three research years, we obtained the several important findings as follows:A.The switch region from the γ subunit of the redox-sensitive chloroplast F1 was introduced into the bacterial F1 and the redox switching of the rotation was revealed. We revealed that the suppressed enzymatic activity of the oxidized Fl was characterized by more frequent long pauses in the rotation behaviour.B.The regulatory function of the γ and ε subunits of chloroplast ATP synthase was studied using the membrane integrated chimeric complex. We concluded that the interaction between these subunits is important for the redox regulation of FoF1 complex by the γ subunit, and a certain structural matching between these regulatory subunits and the catalytic core of the enzyme must be required to confer the redox regulation mechanism to the bacterial FoF1.C.The sensitivity against tentoxin, the specific inhibitor peptide for the chioroplast F1, was conferred to the bacteria Fl by a single amino acid substitution based on the three dimensional structure analysis. Then the rotation of this mutant Fl was investigated in the presence of this inhibitor. The change of the pauses induced by the inhibitor was revealed.