Ubiquitin is a protein modifier in eukaryotes that is involved in various cellular processes, including transcriptional regulation, cell cycle control, and DNA repair. Ubiquitination is comprised of a cascade of E1, E2 and E3 enzymes that results in a covalent bond between the C-terminus of ubiquitin and the epsilon-amino group of a substrate lysine. Ubiquitin-like (Ubl) proteins have similar ubiquitin beta-grasp fold and attach to other proteins in a Ubl manner but with biochemically distinct roles. Ubiquitin (Ub)and Ubl proteins conjugate and deconjugate via ligases and peptidases to covalently modify target polypeptides. Ub includes Ubq/RPL40e and Ubq/RPS27a fusions as well as homopolymeric multiubiquitin protein chains.
Feature 1:E1 interaction site [polypeptide binding site]
Evidence:
Comment:ubiquitin-ubiquitin activating enzyme (E1) interaction site
Comment:ubiquitin is covalently conjugated to its cellular target proteins, by the sequential reactions of Ub-activating (E1), Ub-conjugating (E2), and Ub-protein ligase (E3) enzymes
Structure:3CMM; Saccharomyces cerevisiae ubiquitin-activating enzyme (Uba1) interacts with yeast ubiquitin, contacts at 4A.
Jiyao W et al.(2023). "The conserved domain database in 2023.",