PA_EDEM3_like: protease associated domain (PA) domain-containing EDEM3-like proteins. This group contains various PA domain-containing proteins similar to mouse EDEM3 (ER-degradation-enhancing mannosidase-like 3 protein). EDEM3 contains a region, similar to Class I alpha-mannosidases (gylcosyl hydrolase family 47), N-terminal to the PA domain. EDEM3 accelerates glycoprotein ERAD (ER-associated degradation). In transfected mammalian cells, overexpression of EDEM3 enhances the mannose trimming from the N-glycans, of a model misfolded protein [alpha1-antitrypsin null (Hong Kong)] as well as, from total glycoproteins. Mannose trimming appears to be involved in the selection of ERAD substrates. EDEM3 has a different specificity of trimming than ER alpha-mannosidase 1. The significance of the PA domain to EDEM3 has not been ascertained. It may be a protein-protein interaction domain. At peptidase active sites, the PA domain may participate in substrate binding and/or promoting conformational changes, which influence the stability and accessibility of the site to substrate.
Jiyao W et al.(2023). "The conserved domain database in 2023.",