Activity: Verified in Ubiquitin Charging Assay. Verified in UbiREAL Assay.
Verified Applications: Recombinant Ubiquitin Activating Enzyme 1 activates ubiquitin for subsequent transfer to a Ubiquitin Conjugating Enzyme (E2) in in vitro reactions. This initial event in the ubiquitin-proteasome cascade requires Mg-ATP and 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: MGWSHPQFEKGSHHHHHHHHGSLEVLFQGPGSMSSSPLSKKRRVSGPDPKPGSNCSPAQSVLSEVPSVPTNGMAKNGSEADIDEGLYSRQLYVLGHEAMKRLQTSSVLVSGLRGLGVEIAKNIILGGVKAVTLHDQGTAQWADLSSQFYLREEDIGKNRAEVSQPRLAELNSYVPVTAYTGPLVEDFLSGFQVVVLTNTPLEDQLRVGEFCHNRGIKLVVADTRGLFGQLFCDFGEEMILTDSNGEQPLSAMVSMVTKDNPGVVTCLDEARHGFESGDFVSFSEVQGMVELNGNQPMEIKVLGPYTFSICDTSNFSDYIRGGIVSQVKVPKKISFKSLVASLAEPDFVVTDFAKFSRPAQLHIGFQALHQFCAQHGRPPRPRNEEDAAELVALAQAVNARALPAVQQNNLDEDLIRKLAYVAAGDLAPINAFIGGLAAQEVMKACSGKFMPIMQWLYFDALECLPEDKEVLTEDKCLQRQNRYDGQVAVFGSDLQEKLGKQKYFLVGAGAIGCELLKNFAMIGLGCGEGGEIIVTDMDTIEKSNLNRQFLFRPWDVTKLKSDTAAAAVRQMNPHIRVTSHQNRVGPDTERIYDDDFFQNLDGVANALDNVDARMYMDRRCVYYRKPLLESGTLGTKGNVQVVIPFLTESYSSSQDPPEKSIPICTLKNFPNAIEHTLQWARDEFEGLFKQPAENVNQYLTDPKFVERTLRLAGTQPLEVLEAVQRSLVLQRPQTWADCVTWACHHWHTQYSNNIRQLLHNFPPDQLTSSGAPFWSGPKRCPHPLTFDVNNPLHLDYVMAAANLFAQTYGLTGSQDRAAVATFLQSVQVPEFTPKSGVKIHVSDQELQSANASVDDSRLEELKATLPSPDKLPGFKMYPIDFEKDDDSNFHMDFIVAASNLRAENYDIPSADRHKSKLIAGKIIPAIATTTAAVVGLVCLELYKVVQGHRQLDSYKNGFLNLALPFFGFSEPLAAPRHQYYNQEWTLWDRFEVQGLQPNGEEMTLKQFLDYFKTEHKLEITMLSQGVSMLYSFFMPAAKLKERLDQPMTEIVSRVSKRKLGRHVRALVLELCCNDESGEDVEVPYVRYTIR
Background Information and Alternate Names
Species & domain architecture
UBA1 is a 118 kDa multidomain enzyme: an inactive adenylation domain (IAD) and active adenylation domain (AAD) cradle ATP and ubiquitin (Ub); first/second catalytic cysteine half-domains (FCCH/SCCH) house catalytic Cys632; a ubiquitin-fold domain (UFD) recruits E2s. The doubly loaded UBA1 structure and the E1-E2 thioester mimic illustrate rigid-body rotations that convey Ub from AAD to Cys632 and then toward the E2 active site.
UPS pathway role
UBA1 activates >90 % of cellular ubiquitin, charging broad-specificity E2s (e.g., UBE2D family) as well as specialized E2s like UBE2N. Domain swiveling and an E2-docking “recruitment helix” ensure efficient transthiolation. Its nuclear isoform primes DNA-damage responses, while the cytoplasmic isoform fuels NF-κB and autophagy signaling.
Relevance to TPD & disease biology
Loss-of-function or hypomorphic variants underlie X-linked infantile SMA and adult-onset VEXAS, while hyper-active UBA1 sustains proteostasis in rapidly dividing cancer cells. Small-molecule inhibitors (e.g., TAK-243) trigger catastrophic ubiquitin depletion, synergizing with genotoxic therapies. Recombinant UBA1 is both a potential liability node in some degrader assay designs, and a useful reagent for next-generation E1 inhibitors targeting inflammation, oncology, or neurodegeneration.
References
Olsen, S.K. and C. D. Lima (2013) Mol Cell 49:884-896. PMID 23416107
Schafer, A., et al., (2014) Acta Crystallogr D Biol. Crystallogr.70:1311-1320. PMID 24816100
Groen, E. J. N., and T. H. Gillingwater (2015) Trends Mol Med 21:622-632. PMID
Barghout, S. H., et al., (2019) Leukemia 33:37-51. PMID 29884901
Poulter, J. A., et al., (2021) Blood 137:3676-3681. PMID 33690815
