Most proteins are globular proteins. This page uses the human spliceosomal protein U5-15kD to illustrate some basic features of globular proteins. Specifically:
1. Globular proteins are compact and rarely have internal cavities.
2. Globular protein structure is primarily stabilized by the hydrophobic interaction.
3. Globular proteins have mixed secondary structure.
(U5-15kD is a component of the U5 small nuclear ribosomal protein particle (snRNP). This in turn is a component of the spliceosome, a macromolecular assembly involved in converting primary transcripts into functional mRNAs. U5-15kD was chosen for this page because it is small, but has all of the features necessary to illustrate the points being made.)
The of the protein shows that the protein is compact, globular, and has no signs of internal cavities.
Colouring the shows that the interior of the protein is primarily hydrophobic (red) and the exterior is primarily hydrophilic (blue).
The of the protein shows that the protein has mixed secondary structure. There are three segments of alpha-helix (magenta), six segments of beta-pleated sheet (gold), both parallel and anti-parallel, and some irregular regions (white).
