Claim: Based on evidences of the isolated 20S proteasome complex crystal structure, protein proteasome subunit beta type-3 contributes to form a proteolytic environment for substrate degradation, as one of 28 subunits of 20S proteasome.
Evidence: Crystal structures of isolated 20S proteasome complex demonstrate that the two rings of beta subunits form a proteolytic chamber and maintain all their active sites of proteolysis within the chamber. As one of 28 subunits of 20S proteasome, protein proteasome subunit beta type-3 contributes to form a proteolytic environment for substrate degradation.