Verified Applications: Recombinant Ubiquitin Conjugating Enzyme E2 K accepts activated ubiquitin from Ubiquitin Activating Enzyme 1 (an E1) in in vitro reactions. This charged E2 may subsequently transfer ubiquitin to a protein substrate in an E3 Ligase-catalyzed reaction. Appropriate enzyme concentrations are specific to the application.
2 μg UBE2K 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: GPGSMANIAVQRIKREFKEVLKSEETSKNQIKVDLVDENFTELRGEIAGPPDTPYEGGRYQLEIKIPETYPFNPPKVRFITKIWHPNISSVTGAICLDILKDQWAAAMTLRTVLLSLQALLAAAEPDDPQDAVVANQYKQNPEMFKQTARLWAHVYAGAPVSSPEYTKKIENLCAMGFDRNAVIVALSSKSWDVETATELLLSN
Background Information and Alternate Names
Species & domain architecture
Full-length UBE2K (214 aa) comprises an N-terminal UBC fold (Cys92 active site) and a C-terminal UBA domain (aa 163-214). Crystal and cryo-EM data reveal a monomeric enzyme whose UBA clamps incoming ubiquitin to pre-orient Lys48 for attack, explaining E3-independent chain elongation.
UPS pathway role
UBE2K assembles unanchored or substrate-linked Lys48 polymers that flag proteins for 26S proteasomal degradation. It partners with RING E3s such as RNF2 and TRAF6, and ubiquitylates huntingtin, linking it to polyglutamine neurotoxicity. The UBA also enables Lys48/Lys63-branched chain synthesis on pre-existing K63 substrates, tuning NF-κB and DNA-damage responses.
Relevance to TPD & disease biology
UBE2K is up-regulated in several cancers; an IGF2BP3-UBE2K axis drives pancreatic-ductal-adenocarcinoma stemness and proliferation. Conversely, excessive UBE2K activity promotes huntingtin aggregation, implicating it in Huntington disease. Its strict Lys48 bias and well-defined Ub-binding surfaces make recombinant UBE2K an indispensable scaffold for degrader design, proteasome-tuning drug screens, and linkage-specific tool validation.
References
Kalchman, M. A., et al., (1996) J Biol Chem 271:19385-19394. PMID
Middleton A.J., and C.L. Day (2015) Sci Rep 5:16793. PMID 26592444
Pluska, L., et al., (2021) EMBO J 40:e106094. PMID 33576509
Nakasone, M. A., et al., (2022) Nat Chem Biol 18:422-431. PMID 35027744
Fu, W., et al., (2023) Int J Oncol 62:52. PMID
