Architecture of the ATP-driven motor for protein import into chloroplasts  

作　　者：Ning Wang Jiale Xing Xiaodong Su Junting Pan Hui Chen Lifang Shi Long Si Wenqiang Yang Mei Li 

机构地区：[1]Key Laboratory of Biomacromolecules(CAS),National Laboratory of Biomacromolecules,CAS Center for Excellence in Biomacromolecules,Institute of Biophysics,Chinese Academy of Sciences,Beijing 100101,China [2]Photosynthesis Research Center,Key Laboratory of Photobiology,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China [3]University of Chinese Academy of Sciences,Beijing,China [4]China National Botanical Garden,Beijing 100093,China [5]Institute of Botany,Chinese Academy of Sciences,Beijing,China [6]Key Laboratory of Epigenetic Regulation and Intervention,Chinese Academy of Sciences Center for Excellence in Molecular Cell Science,Shanghai Institute of Biochemistry and Cell Biology,Chinese Academy of Sciences,Shanghai 200031,China

出　　处：《Molecular Plant》2024年第11期1702-1718,共17页分子植物（英文版）

基　　金：funded by the Strategic Priority Research Program of CAS(XDB37020101);the National Key R&D Program of China(2021YFA0910800);the National Natural Science Foundation of China(31930064);the Youth Innovation Promotion Association,Chinese Academy of Sciences(Y2022038);the Regional Joint Key Projects of the National Foundation of China(U22A20445);the Natural Science Foundation of Shandong Province(ZR2023ZD30).

摘　　要：Thousands of nuclear-encoded proteins are transported into chloroplasts through the TOC–TIC translocon that spans the chloroplast envelope membranes.A motor complex pulls the translocated proteins out of the TOC–TIC complex into the chloroplast stroma by hydrolyzing ATP.The Orf2971–FtsHi complex has been suggested to serve as the ATP-hydrolyzing motor in Chlamydomonas reinhardtii,but little is known about its architecture and assembly.Here,we report the 3.2-Åresolution structure of the Chlamydomonas Orf2971–FtsHi complex.The 20-subunit complex spans the chloroplast inner envelope,with two bulky modules protruding into the intermembrane space and stromal matrix.Six subunits form a hetero-hexamer that potentially provides the pulling force through ATP hydrolysis.The remaining subunits,including potential enzymes/chaperones,likely facilitate the complex assembly and regulate its proper function.Taken together,our results provide the structural foundation for a mechanistic understanding of chloroplast protein translocation.

关 键 词：chloroplast protein translocation cryo-EM structure Orf2971–FtsHi ATP-driven motor CHLAMYDOMONAS 

分 类 号：Q94[生物学—植物学]