Proteasome 26S Subunit, Non ATPase 13 (PSMD13)

The 26S proteasome is a multicatalytic proteinase complex with a highly ordered structure composed of 2 complexes, a 20S core and a 19S regulator.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.

PSMD13 encodes a non-ATPase subunit of the 19S regulator. Two transcripts encoding different isoforms have been described. The deduced 376-amino acid protein has a calculated molecular mass of 42.9 kD, and it shares 97% identity with mouse S11. Western blot analysis detected S11 at about 43 kD.