?
 
ubiquitin-like (Ubl) domain found in ubiquitin-like protein 5 (UBL5) and similar proteins UBL5, known as Hub1 in yeast, is an atypical ubiquitin-like (Ubl) post-translational modifier that contains a conserved Ubl domain with a beta-grasp Ubl fold. At the C-terminal end of its Ubl fold is a di-tyrosine motif followed by a single variable residue instead of the characteristic di-glycine found in all other Ubl modifiers, and thus UBL5 does not form covalent conjugates with cellular proteins. The yeast Hub1p binds non-covalently to the HIND element of spliceosomal protein Snu66p (Snu66p is termed SART1 in mammals) and modifies the spliceosome by this unconventional Ubl modifier. In higher eukaryotes, UBL5/Hub1 plays a role in modulating pre-mRNA splicing. It also is required for signaling in the mitochondrial unfolded protein response, through interaction with the transcription factor DVE-1 and upregulation of chaperone genes in response to mitochondrial stress. Moreover, UBL5 functions as a factor that directly binds to and stabilizes FANCI, and promotes the functionality of the Fanconi anemia (FA) DNA repair pathway. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",