Institute of Plant Genetics, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany.
Department of Structural Biology, Max-Planck-Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt, Germany.
Trends Plant Sci. 2024 Jan;29(1):64-71. doi: 10.1016/j.tplants.2023.07.007. Epub 2023 Aug 19.
The mitochondrial NADH-dehydrogenase complex of the respiratory chain, known as complex I, includes a carbonic anhydrase (CA) module attached to its membrane arm on the matrix side in protozoans, algae, and plants. Its physiological role is so far unclear. Recent electron cryo-microscopy (cryo-EM) structures show that the CA module may directly provide protons for translocation across the inner mitochondrial membrane at complex I. CAs can have a central role in adjusting the proton concentration in the mitochondrial matrix. We suggest that CA anchoring in complex I represents the original configuration to secure oxidative phosphorylation (OXPHOS) in the context of early endosymbiosis. After development of 'modern mitochondria' with pronounced cristae structures, this anchoring became dispensable, but has been retained in protozoans, algae, and plants.
线粒体呼吸链中的 NADH 脱氢酶复合物，即复合物 I，在原生动物、藻类和植物中，其膜臂的基质侧连接有碳酸酐酶 (CA) 模块。其生理作用目前尚不清楚。最近的电子冷冻显微镜 (cryo-EM) 结构表明，CA 模块可能直接为复合物 I 中的质子跨线粒体内膜转运提供质子。CA 可以在调节线粒体基质中的质子浓度方面发挥核心作用。我们认为，CA 在复合物 I 中的锚定代表了原始的构象，以确保早期内共生体中的氧化磷酸化 (OXPHOS)。在具有明显嵴结构的“现代线粒体”发展之后，这种锚定变得可有可无，但在原生动物、藻类和植物中仍然存在。
