UBR-box found in ubiquitin-protein ligases, E3-alpha-1 (UBR1), E3-alpha-2 (UBR2), and similar proteins
This family includes UBR1 and UBR2 (both EC 2.3.2.27). Both UBR1 (also called E3alpha-I or N-recognin-1) and UBR2 (also called E3-alpha-II or N-recognin-2), 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. Deficiency of UBR1 causes Johanson-Blizzard syndrome. UBR2 is associated with chromatin and controls chromatin dynamics and gene expression in both germ cells and somatic cells. It plays an important role in spermatogenesis.
Jiyao W et al.(2023). "The conserved domain database in 2023.",