CUEDC1 contains 1 CUE domain. The CUE domain is structurally related to the ubiquitin-binding UBA domain and has been reported to exist as a domain-swapped dimer that makes additional contacts with ubiquitin, and consequently, binds ubiquitin with higher affinity. The CUE domain is found in proteins with diverse functions including degradation of misfolded proteins in the endoplasmic reticulum and protein sorting. Recombinant human CUEDC1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.