5XTE

Cryo-EM structure of human respiratory complex III (cytochrome bc1 complex)

Summary for 5XTE

• Entry DOI: 10.2210/pdb5xte/pdb
• EMDB information: 6774
• Descriptor: Cytochrome b-c1 complex subunit 8, Cytochrome b-c1 complex subunit 2, mitochondrial, Cytochrome b-c1 complex subunit 1, mitochondrial, ... (17 entities in total)
• Functional Keywords: respiratory, oxidoreductase-electron transport complex, oxidoreductase/electron transport
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 22
• Total formula weight: 497160.62

Authors

Gu, J.,Wu, M.,Yang, M. (deposition date: 2017-06-19, release date: 2017-08-30, Last modification date: 2019-11-20)

Primary citation

Guo, R.,Zong, S.,Wu, M.,Gu, J.,Yang, M.
Architecture of Human Mitochondrial Respiratory Megacomplex I2III2IV2.
Cell, 170:1247-1257.e12, 2017

PubMed Abstract: The respiratory megacomplex represents the highest-order assembly of respiratory chain complexes, and it allows mitochondria to respond to energy-requiring conditions. To understand its architecture, we examined the human respiratory chain megacomplex-IIIIIV (MCIIIIIV) with 140 subunits and a subset of associated cofactors using cryo-electron microscopy. The MCIIIIIV forms a circular structure with the dimeric CIII located in the center, where it is surrounded by two copies each of CI and CIV. Two cytochrome c (Cyt.c) molecules are positioned to accept electrons on the surface of the c state CIII dimer. Analyses indicate that CII could insert into the gaps between CI and CIV to form a closed ring, which we termed the electron transport chain supercomplex. The structure not only reveals the precise assignment of individual subunits of human CI and CIII, but also enables future in-depth analysis of the electron transport chain as a whole.

PubMed: 28844695
DOI: 10.1016/j.cell.2017.07.050

Experimental method

ELECTRON MICROSCOPY (3.4 Å)