Proteasomes break down other proteins. They help keep the cell free of damaged proteins as well as allowing the cell to recycle parts of proteins that it no longer uses. In this image, the yellow and red core is where the proteins are broken down. The blue ends recognize ubiquitin tagged proteins and starts pulling them in, while the pink part unfolds them and passes them in to the core.
This protein reminded me of a pencil sharpener, especially the twisted core in the middle. The core reminded me of the center of a classroom pencil sharpener, and the outer parts of the protein are kind of similar to the holes in a pencil sharpener that only let the right size of pencil through. If you attached two pencil sharpeners back to back and put on a casing that looked more like the protein shape, you could have a fairly accurate representation of a proteasome that would also be able to sharpen two pencils at the same time.
