cd16660: RING-Ubox_RNF37 (this model, PSSM-Id:319574 is obsolete and has been replaced by 438322)
U-box domain, a modified RING finger, found in RING finger protein 37 (RNF37)
RNF37, also known as KIAA0860, U-box domain-containing protein 5 (UBOX5), UbcM4-interacting protein 5 (UIP5), or ubiquitin-conjugating enzyme 7-interacting protein 5, is an E3 ubiquitin-protein ligase found exclusively in the nucleus as part of a nuclear dot-like structure. It interacts with the molecular chaperone VCP/p97 protein. RNF37 contains a U-box domain followed by a potential nuclear location signal (NLS), and a C-terminal C3HC4-type RING-HC finger. The U-box domain is a modified RING finger domain that lacks the hallmark metal-chelating cysteines and histidines of the latter, but is likely to adopt a RING finger-like conformation. The presence of the U-box, but not of the RING finger, is required for the E3 activity. The U-box domain can directly interact with several E2 enzymes, including UbcM2, UbcM3, UbcM4, UbcH5, and UbcH8, suggesting a similar function as the RING finger in the ubiquitination pathway. This family corresponds to the U-box domain.
Feature 1:U-box domain, a modified RING finger [structural motif]
Evidence:
Comment:The U-box is a modified form of the RING finger domain that lacks metal chelating cysteines and histidines. Like the RING finger, the U-box is thought to form a structure consisting of three beta-sheets and a single alpha-helix, which would be stabilized by salt bridges instead of chelated metal ions.
Jiyao W et al.(2023). "The conserved domain database in 2023.",