Virtuelle (Nano) Welten: PDB Molecule of the Month 5: Cytochrome C Oxydase

Exploring the Structure

Cytochrome c oxidase uses several metal ions to shuffle electrons onto oxygen molecules. Two copper atoms, shown in green at the top, are thought to be the port for entry. This is denoted as site "A" and is very close to the region that binds to cytochrome c (not shown), the small protein that delivers electrons to cytochrome c oxidase. The oxygen molecule itself binds lower, in the middle of the enzyme. The oxygen is pinioned between a heme iron atom (shown in yellow) and another copper atom, denoted as site "B." A second heme group, off to the left in this picture, assists in the transfer of electrons. The structure shown here, PDB entry 1oco, has a carbon monoxide molecule bound in the active site, blocking the binding of oxygen and poisoning function of the enzyme.
This picture was created in RasMol by drawing a backbone for the protein atoms and spacefilling spheres for all non-protein atoms. You can create similar pictures by going to PDB entry 1oco and clicking "View Structure."