Proteasome

A proteasome is a multi-protein complex that can digest other proteins into short polypeptides and amino acids in an ATP-driven reaction. The proteasome is hollow, providing an enclosed space for protein digestion, and has openings at two ends to allow entry of the targetted protein.

For a description of the unit S, see Svedberg. For Å, see Angstrom.

26S proteasome The 26S proteasome is used for the digestion of ubiquitin-marked proteins. It consists of a 19S and a 20S unit. The 20S unit consists of 14 α and 14 β subunits. It is about 150Å long and 115Å wide.