Understanding the 3-dimensional structures of proteins is key to understanding their functions. Identifying the positions of all the different atoms that make up an individual protein (there are usually several thousand atoms in a single protein) is a big job, but once achieved, we can use a range of tools to visualise protein structures. Here, we'll have a look at some different ways of representing molecular structures of proteins, and in so doing, start to see the key structural elements that characterise protein structure.
The view on the right shows a model of chymotrypsin, an enzyme that digests proteins in the gut. This is a so-called 'spacefill' view, in which each atom is shown as a sphere. Different atoms are coloured individually: grey = carbon, red = oxygen, blue = nitrogen, etc.
In spacefill view, we can see the overall shape of the protein, but not much else. We cant see what's going on inside, for example.
This view shows chymotrypsin in the familiar representation. Atoms are indicated by small spheres, with the sticks that link them together representing covalent bonds.
