19S proteasome (PA700 complex)

Function

• two 19S regulatory caps at the end of the 20S proteasome barrel form the 26S proteasome
• the 19S caps mediate recognition of polyubiquitin & unfold the target protein for degradation
• activates proteolytic activity of 20S proteasome

Structure

• consists of 28 subunits arranged to form a cylinder-shaped complex by 4 stacked rings, each containing 7 subunits

More general terms

• macromolecular complex

Component of

• 26S proteasome