UBR-box found in UBR4, UBR5, UBR6/FBOX11, UBR7 and similar proteins
This family includes UBR4 (EC 2.3.2.27), UBR5 (EC 2.3.2.26), UBR6/FBOX11 and UBR7 (EC 2.3.2.27). Both UBR4 (also called 600 kDa retinoblastoma protein-associated factor, or N-recognin-4, or retinoblastoma-associated factor of 600 kDa, or RBAF600, or p600, or zinc finger UBR1-type protein 1) and UBR7 (also called N-recognin-7) are RING-type E3 ubiquitin ligases of the Arg/N-end rule degradation pathway. They recognize and bind to proteins bearing specific N-terminal residues that are destabilizing according to the N-end rule, leading to their ubiquitination and subsequent degradation. UBR5 (also called E3 ubiquitin-protein ligase, HECT domain-containing 1, E3 ligase identified by differential display (EDD), hyperplastic discs protein homolog (HYD), progestin-induced protein, or N-recognin-5) is a HECT (homologous to E6-AP C-terminus)-type E3 ubiquitin-protein ligase that acts as a key regulator of the ubiquitin proteasome system in both cancer and developmental biology. It is required for Wnt signal responses in Drosophila and human cell lines downstream of activated Armadillo/beta-catenin. It also plays a key role in ciliogenesis by regulating centriolar satellite stability and primary cilia. UBR6 (also called FBOX11, protein arginine N-methyltransferase 9 (PRMT9), or vitiligo-associated protein 1 (VIT-1)), is an E3 ubiquitin ligase and a type II methyltransferase, which functions as a key regulator of tumor initiation and progression. UBR6 is a substrate recognition component of a SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins, such as DTL/CDT2, BCL6 and PRDM1/BLIMP1. UBR6 does not bind N-terminal signals.
Jiyao W et al.(2023). "The conserved domain database in 2023.",