20S Proteasome _3, C10 II, HC10 II, proteasome prosome, macropain subunit, beta type 3, Proteasome beta 3 subunit, Proteasome chain 13, proteasome component C10 II, Proteasome theta chain, PSMB3.
The proteasome is a multicatalytic proteinase complex with a highly ordered ring shaped 20S core structure. The core structure is composed of 4 rings of 28 non identical subunits, 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin dependent process in a non lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides.