Cytochrome b model viewed parallel to the membrane. The structure is color coded on a "rainbow" scale (red for high values - yellow - green - blue - grey for low values), to indicate the degree of conservation.
View from the side with helices C and D exposed. The red patch at lower right is the conserved surface. Note the blue patch at left contributed by helix E which is conserved only at its cytoplasmic end (near cyt bH).
View from the side with helices B and F exposed. The yellow patch at lower left is the conserved surface. Note the blue patch at right contributed by helix A, which shows a strong conservation moment, with the unconserved side placed out in the model (see above).