Cytochrome C Oxidase - energy transducer, electron carrier.

Views

Original settings

    Might have to click twice to get the proper enzyme orientation.

 

Colored chains

    Note the dimeric structure of the enzyme - the large number of colors resulting is from the 26 discrete chains in Cyt. C Oxidase (13 in each dimer).  Push this button to see colored chains in any view.

 

Colors off

    Push this at any time to restore CPK coloring.

 

Protein backbone

 

Protein backbone with spacefilling heme/metal sites

 

Protein backbone with cytochrome C binding sites and heme/metal groups

    This view will color the cytochrome C binding sites green and the heme/metal sites cyan.  Composed of solely Asp and Glu residues, these concave binding sites stabilize the binding of cytochrome C to the enzyme.  Observe the close proximity of the binding sites to the heme/metal centers.

Cartoon view

 

Cartoon view with alpha-helix coloring

    Observe the large number of helices that extend across the mitochondiral membrane.

 

Charge density of the enzyme

    This view will color the charged atoms in the enzyme blue - notice that charge density is concentrated in non-transmembrane sections of the protein.

 

Protein hydrophobicity

    This changes the color of the polar atoms in the enzyme blue and the hydrophobic green - much like the charge density view, note the hydrophobicity of the transmembrane helices even in the presence of polar molecules.

 

The two heme/metal sites - spacefilling

    300% zoom.  Move the picture around to get a good look at the sites.

 

Coordination of the heme in the metal sites

    The hemes in this enzyme are coordinated by three Histidine residues each - all from the A and N chains of the dimers (A chain for one dimer, N for the other).  The labels are shown for His 61, 376, and 378.

 

 

Cytochrome C Oxidase is brought to you by: Nate Rose and Brian White