1. bc1 complex
Stuart Rose

2. Goal of this presentation:
Function of bc1 complex
Overall Structure
Structural Details Related to Function

3. bc1 complex function Cytochrome bc1 complex or
ubiquinol:cytochrome c oxidoreductase
“Proton pump”: proton translocation coupled to electron transfer
FOR MORE INFO...
Prof. Crofts’ bc1 Complex Site

4. Full Dimer
Two monomers with two fold symmetry. Shown here generally colored by chain designation and axis of symmetry located along a vertical line the image plane.

5. Functional Highlights: Qo Site
Qo site: oxidation of quinol, QH2,to quinone, Q
Conformation of site: Liganding of Q within pocket and Liganding of different inhibitor types within pocket
Movement of Reiske Iron Sulfer Protein (ISP) between two domains: oxidation of quinol to reduction of cytochrome c1 at heme propianate of the cytochrome

6. Schematic view of Q-cycle:

7. bc1 complex subunits of interest

8. Reiske (ISP) Binding Domains
Cyt b
ISP
Cyt c1

9. Electron Transfer From ISP to cyt c1 and cyt b

10. Qo Site with Stigmatellin

11. Quinone, Q, vs Stigmatellin
Oxidized by ISP
Reduces bl
Quinol, QH2, orthographic view
ISP interaction
Interference
with proximate zone
Stigmatellin, perspective view

12. Distances between redox centers proximal to Qo-site

13. an electrons view….

14. Ligation of hemes in Cyt b