Introduction

What is the 20S proteasome?
Large, macromolecular protease
28 subunits
Up to 14 active sites per molecule
Core of 26S proteasome

Involved in
Intracellular protein turnover
2% of total cellular protein
main non-lysozomal protein degradation pathway
Ubiquitin-proteasome pathway (eukaryotes)
MHC class I peptide antigen generation