研究人员表明，一个包含所有四个呼吸链组件的超级复合物对纤毛虫的膜曲率诱导有贡献。研究人员报告了超级复合物的冷冻电镜和低温层析结构，该复合物包括150种不同的蛋白质和311种结合的脂质，形成一个稳定的5.8-MDa组件。由于亚单位的获得和延伸，复合体I与复合体IV二聚体结合，产生了一个楔形缺口，作为复合体II的结合点。与倾斜的复合体III二聚体联合，它导致了一个弯曲的膜区域。
利用分子动力学模拟，研究人员证明了不同的超级复合体主动地促进了膜曲率的诱导和嵴的管腔化。这些发现强调了呼吸复合体的蛋白亚单位的演化如何导致了I-II-III2-IV2超级复合体，它有助于生物能膜的塑造，从而使其功能专业化。
研究人员表示，线粒体的能量转换需要线粒体内膜的复杂结构。
附：英文原文
Title: Structural basis of mitochondrial membrane bending by the I–II–III2–IV2 supercomplex
Author: Mhleip, Alexander, Flygaard, Rasmus Kock, Baradaran, Rozbeh, Haapanen, Outi, Gruhl, Thomas, Tobiasson, Victor, Marchal, Amandine, Sharma, Vivek, Amunts, Alexey
Issue&Volume: 2023-03-22
Abstract: Mitochondrial energy conversion requires an intricate architecture of the inner mitochondrial membrane1. Here we show that a supercomplex containing all four respiratory chain components contributes to membrane curvature induction in ciliates. We report cryo-electron microscopy and cryo-tomography structures of the supercomplex that comprises 150 different proteins and 311 bound lipids, forming a stable 5.8-MDa assembly. Owing to subunit acquisition and extension, complex I associates with a complex IV dimer, generating a wedge-shaped gap that serves as a binding site for complex II. Together with a tilted complex III dimer association, it results in a curved membrane region. Using molecular dynamics simulations, we demonstrate that the divergent supercomplex actively contributes to the membrane curvature induction and tubulation of cristae. Our findings highlight how the evolution of protein subunits of respiratory complexes has led to the I–II–III2–IV2 supercomplex that contributes to the shaping of the bioenergetic membrane, thereby enabling its functional specialization.
DOI: 10.1038/s41586-023-05817-y
Source: https://www.nature.com/articles/s41586-023-05817-y
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
