拟南芥叶绿体 NADH 脱氢酶样复合物与光合系统 I 的超分子组装。

Supramolecular assembly of chloroplast NADH dehydrogenase-like complex with photosystem I from Arabidopsis thaliana.

机构信息

National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China; University of Chinese Academy of Sciences, Beijing 100049, P.R. China.

National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China.

出版信息

Mol Plant. 2022 Mar 7;15(3):454-467. doi: 10.1016/j.molp.2022.01.020. Epub 2022 Feb 2.

DOI:10.1016/j.molp.2022.01.020

PMID:35123031

Abstract

Cyclic electron transport/flow (CET/CEF) in chloroplasts is a regulatory process essential for the optimization of plant photosynthetic efficiency. A crucial CEF pathway is catalyzed by a membrane-embedded NADH dehydrogenase-like (NDH) complex that contains at least 29 protein subunits and associates with photosystem I (PSI) to form the NDH-PSI supercomplex. Here, we report the 3.9 Å resolution structure of the Arabidopsis thaliana NDH-PSI (AtNDH-PSI) supercomplex. We constructed structural models for 26 AtNDH subunits, among which 11 are unique to chloroplasts and stabilize the core part of the NDH complex. In the supercomplex, one NDH can bind up to two PSI-light-harvesting complex I (PSI-LHCI) complexes at both sides of its membrane arm. Two minor LHCIs, Lhca5 and Lhca6, each present in one PSI-LHCI, interact with NDH and contribute to supercomplex formation and stabilization. Collectively, our study reveals the structural details of the AtNDH-PSI supercomplex assembly and provides a molecular basis for further investigation of the regulatory mechanism of CEF in plants.

摘要

叶绿体中的循环电子传递/流（CET/CEF）是优化植物光合作用效率所必需的调节过程。一个关键的 CEF 途径是由一个膜嵌入的 NADH 脱氢酶样（NDH）复合物催化的，该复合物至少包含 29 个蛋白亚基，并与光系统 I（PSI）结合形成 NDH-PSI 超复合物。在这里，我们报告了拟南芥 NDH-PSI（AtNDH-PSI）超复合物的 3.9Å分辨率结构。我们构建了 26 个 AtNDH 亚基的结构模型，其中 11 个是叶绿体特有的，稳定了 NDH 复合物的核心部分。在超复合物中，一个 NDH 可以在其膜臂的两侧结合多达两个 PSI-光捕获复合物 I（PSI-LHCI）复合物。两个较小的 LHCIs，Lhca5 和 Lhca6，每个都存在于一个 PSI-LHCI 中，与 NDH 相互作用，有助于超复合物的形成和稳定。总的来说，我们的研究揭示了 AtNDH-PSI 超复合物组装的结构细节，并为进一步研究植物 CEF 的调节机制提供了分子基础。