Complex IV Cytochrome c Oxidase

3D ModelNoAI

Complex IV is the last protein complex in the electron transport chain (ETC). It is a homodimer with a docking site for cytochrome c. CIV is the only protein complex in the ETC in which electrons travel down from the intermembrane space side to the matrix side against the charge gradient to O2. CIV contains a binuclear copper site CuA, CuB, and two heme groups, a and a3.

CIV catalyzes the reduction of O2 to water at the binuclear site of heme a3 and CuB using protons extracted from the mitochondrial matrix and electrons delivered by cytochrome c. This reaction is coupled by translocation of protons across the mitochondrial inner membrane.

This model was created using ChimeraX from x-ray diffraction structure data in the Protein Data Bank (PDB ID 1OCR). PDB DOI: 10.2210/pdb1OCR/pdb & https://www.cgl.ucsf.edu/chimerax/

Yoshikawa S, et al. (1998). Redox-Coupled Crystal Structural Changes in Bovine Heart Cytochrome c Oxidase. Science 280: 1723–1729. https://doi.org/10.1126/science.280.5370.1723