Activity: Verified in K48-linked Di-ubiquitin Hydrolysis Assay.
Verified Applications: Recombinant human OTUB1* is a Ubiquitin-specific deconjugating fusion-enzyme that is highly specific for K48-linked poly-ubiquitin. Appropriate enzyme concentrations are specific to the application.
2 μg UBA1 run on 4-12% SDS-PAGE gel under reducing conditions, then visualized with Colloidal Coomassie Blue Stain.
Formulation: 40 mM HEPES, 100 mM NaCl, 10% Glycerol, 1 mM EDTA, 1 mM TCEP, pH 7.6
Shipping: The product is shipped with dry ice or equivalent. Upon receipt, store it immediately at the temperature recommended below.
Storage and Stability: Use a manual defrost freezer and avoid repeated freeze-thaw cycles. Aliquot and store ≤ -70°C (stable for 24 months from date of receipt).
Protein Sequence: GPGSMALKRIHKELNDLARDPPAQCSAGPVGDDMFHWQATIMGPNDSPYQGGVFFLTIHFPTDYPFKPPKVAFTTRIYHPNINSNGSIALDILRSQWSPALTISKVLLSICSLLCDPNPDDPLVPEIARIYKTDREKYNRIAREWTQKYAMGGSSGGSSGGSDSEGVNCLAYDEAIMAQQDRIQQEIAVQNPLVSERLELSVLYKEYAEDDNIYQQKIKDLHKKYSYIRKTRPDGNCFYRAFGFSHLEALLDDSKELQRFKAVSAKSKEDLVSQGFTEFTIEDFHNTFMDLIEQVEKQTSVADLLASFNDQSTSDYLVVYLRLLTSGYLQRESKFFEHFIEGGRTVKEFCQQEVEPMCKESDHIHIIALAQALSVSIQVEYMDRGEGGTTNPHIFPEGSEPKVYLLYRPGHYDILYK
Background Information and Alternate Names
Species & domain architecture
Human OTUB1 (271 aa) comprises an N-terminal helical extension that binds charged E2-Ub complexes, followed by the catalytic OTU domain housing the Cys91–His265–Asp268 triad. Crystal structures of OTUB1 in complex with UBE2D-Ub (PDB 4DDI) reveal how the N-terminal helix and distal S1/S1′ pockets cooperate with the E2 backside to enforce OTUB1’s Lys48 specificity.
UPS pathway role
OTUB1 erases Lys48 poly-ubiquitin chains and, uniquely, allosterically locks E2 enzymes (UBE2D/UBE2N families) in an inactive conformation, halting chain elongation without hydrolysis. This dual mode of action safeguards DNA-damage signaling, stabilizes p53 and RACK1, and tempers TGF-β and NF-κB outputs.
Relevance to TPD & disease biology
Dysregulated OTUB1 drives oncogenic survival, hepatocyte necroptosis and aberrant immune activation; conversely, its E2-blocking mode is being co-opted in DUB-TACs to stabilize mis-folded CFTR and other therapeutic targets.
References
Juang, Y-C., et al., (2012) Mol Cell 45(3):384-97. PMID 22325355
Wu M., et al., (2024). Front Mol Biosci 10:1261273. PMID 38264570.
Alternate Names: OTB1, OTU1); The “star” suffix denotes fusion to UBE2D1(C85A), an inert isoform of the ubiquitin-conjugating enzyme UBC H5a.
