Non-catalytic component of the 20S core proteasome complexinvolved in the proteolytic degradation of most intracellular proteins. This complex plays numerous essential roles within the cell byassociating with different regulatory particles. Associated with two19S regulatory particles, forms the 26S proteasome and thusparticipates in the ATP-dependent degradation of ubiquitinatedproteins. The 26S proteasome plays a key role in the maintenance ofprotein homeostasis by removing misfolded or damaged proteins thatcould impair cellular functions, and by removing proteins whosefunctions are no longer required. Associated with the PA200 or PA28, the 20S proteasome mediates ubiquitin-independent protein degradation. This type of proteolysis is required in several pathways includingspermatogenesis (20S-PA200 complex) or generation of a subset of MHCclass I-presented antigenic peptides (20S-PA28 complex). [1-3]

MLSSTAMYSAPGRDLGMEPHRAAGPLQLRFSPYVFNGGTILAIAGEDFAIVASDTRLSEGFSIHTRDSPKCYKLTDKTVIGCSGFHGDCLTLTKIIEARLKMYKHSNNKAMTTGAIAAMLSTILYSRRFFPYYVYNIIGGLDEEGKGAVYSFDPVGSYQRDSFKAGGSASAMLQPLLDNQVGFKNMQNVEHVPLSLDRAMRLVKDVFISAAERDVYTGDALRICIVTKEGIREETVSLRKD