PSMD5 also known as 26S proteasome non-ATPase regulatory subunit 5 isoform 1. The 26S proteasome is an enzymatic complex that degrades ubiquitinated proteins in eukaryotic cells. PSMD5 is one of a number of chaperones that are involved in the assembly of the proteasome. The chaperones dissociate before 26S proteasome formation is complete. Recombinant human PSMD5, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques