Structure of the intact 14-subunit human cytochrome c oxidase.
Zong, S., Wu, M., Gu, J., Liu, T., Guo, R., Yang, M.(2018) Cell Res 28: 1026-1034
- PubMed: 30030519 
- DOI: https://doi.org/10.1038/s41422-018-0071-1
- Primary Citation of Related Structures:  
5Z62 - PubMed 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.
Organizational Affiliation: 
Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.