Structure of the intact 14-subunit human cytochrome c oxidase

作者：Shuai Zong, Meng Wu, Jinke Gu, Tianya Liu, Runyu Guo, Maojun Yang · 发表于：Cell Research · 年份：2018 · DOI：10.1038/s41422-018-0071-1 · 被引用次数：249 · 研究领域：Photosynthetic Processes and Mechanisms、Mitochondrial Function and Pathology、DNA Repair Mechanisms

Abstract Respiration is one of the most basic features of living organisms, and the electron transport chain complexes are probably the most complicated protein system in mitochondria. Complex-IV is the terminal enzyme of the electron transport chain, existing either as randomly scattered complexes or as a component of supercomplexes. NDUFA4 was previously assumed as a subunit of complex-I, but recent biochemical data suggested it may be a subunit of complex-IV. However, no structural evidence supporting this notion was available till now. Here we obtained the 3.3 Å resolution structure of complex-IV derived from the human supercomplex I 1 III 2 IV 1 and assigned the NDUFA4 subunit into complex-IV. Intriguingly, NDUFA4 lies exactly at the dimeric interface observed in previously reported crystal structures of complex-IV homodimer which would preclude complex-IV dimerization. Combining previous structural and biochemical data shown by us and other groups, we propose that the intact complex-IV is a monomer containing 14 subunits.