What is the Role of Ubiquitin in Proteasome-Mediated Catalysis?
Ubiquitin is a small protein that tags substrates for degradation by the proteasome. This process, known as ubiquitination, involves the attachment of ubiquitin to lysine residues on the substrate protein. Ubiquitin chains are recognized by the 19S regulatory particles of the proteasome, which then facilitate the unfolding and translocation of the substrate into the 20S core. Ubiquitination ensures specificity in protein degradation, allowing the cell to precisely regulate protein turnover.
