PNGase/UBA or UBX (PUB) domain of plant Ubiquitin-associated (UBA) domain containing proteins
The PUB domain functions as a p97 (also known as valosin-containing protein or VCP) adaptor by interacting with the D1 and/or D2 ATPase domains. The type II AAA+ ATPase p97 is involved in a variety of cellular processes such as the deglycosylation of ERAD substrates, membrane fusion, transcription factor activation and cell cycle regulation through differential binding to specific adaptor proteins. The UBA domain, along with UBL (ubiquitin-like) domain, has been implicated in proteasomal degradation by associating with substrates destined for degradation as well as with subunits of the proteasome, thus regulating protein turnover. This family contains only plant UBA domain-containing proteins.