Caption:The purple ribbon indicates the shape of the polypeptide backbone. All the side chains, shown as ball-and-stick models, project outward from the helix axis. This example is from residues Ile-355 (bottom) to Gly-365 (top) of horse liver alcohol dehydrogenase. Some hydrogen atoms are not shown. [PDB 1ADF]
Notes:In this model of horse liver alcohol dehydrogenase, blue=nitrogen, red=oxygen, gray=carbon, white=hydrogen. This helix is also explored in figure 4.12 and 4.13. The texbook version of this figure shows the helix in stereo format.