Ub-Cys632-UBA1 adenylates ubiquitin in the cytosol

Stable Identifier
R-HSA-8852132
Type
Reaction
Species
Homo sapiens
Compartment
Locations in the PathwayBrowser
Summation

Activation of ubiquitin by UBA1 proceeds through 3 steps: adenylation of ubiquitin, conjugation of ubiquitin from adenyl-ubiquitin to an internal cysteine residue of UBA1, and adenylation of a second molecule of ubiquitin. In the third step, the UBA1-ubiquitin conjugate adenylates the C-terminal glycine of a second ubiquitin molecule. This results in UBA1 loaded with 2 ubiquitin molecules, one of which is conjugated to an internal cysteine residue of UBA1 and one of which is adenylated and non-covalently bound to UBA1 (Jin et al. 2007, inferred from the rabbit homologue in Haas et al. 1982, Hershko et al. 1983, reviewed in Groettrup et al. 2008).

Literature References
PubMed ID Title Journal Year
18353650 Activating the ubiquitin family: UBA6 challenges the field

Groettrup, M, Pelzer, C, Schmidtke, G, Hofmann, K

Trends Biochem. Sci. 2008
17597759 Dual E1 activation systems for ubiquitin differentially regulate E2 enzyme charging

Jin, J, Li, X, Gygi, SP, Harper, JW

Nature 2007
6277905 Ubiquitin-activating enzyme. Mechanism and role in protein-ubiquitin conjugation

Haas, AL, Warms, JV, Hershko, A, Rose, IA

J. Biol. Chem. 1982
6305978 Components of ubiquitin-protein ligase system. Resolution, affinity purification, and role in protein breakdown

Hershko, A, Heller, H, Elias, S, Ciechanover, A

J. Biol. Chem. 1983
Participants
Participant Of
Catalyst Activity
Catalyst Activity
Title
ubiquitin activating enzyme activity of Ub-Cys632-UBA1 [cytosol]
Physical Entity
Activity
Orthologous Events
Authored
Reviewed
Created