Ub-Cys625-UBA6 adenylates ubiquitin in the cytosol

Stable Identifier
Reaction [transition]
Homo sapiens
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As inferred from the homologous UBA1, activation of ubiquitin by UBA6 (UBE1L1) proceeds through 3 steps: adenylation of ubiquitin, conjugation of ubiquitin from adenyl-ubiquitin to an internal cysteine residue of UBA6, and adenylation of a second molecule of ubiquitin. In the third step, the UBA6-ubiquitin conjugate adenylates the C-terminal glycine of a second ubiquitin molecule. This results in UBA6 loaded with 2 ubiquitin molecules, one of which is conjugated to an internal cysteine residue of UBA6 and one of which is adenylated and non-covalently bound to UBA6 (Jin et al. 2007, Pelzer et al. 2007, reviewed in Groettrup et al. 2008).
Literature References
PubMed ID Title Journal Year
17597759 Dual E1 activation systems for ubiquitin differentially regulate E2 enzyme charging

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

Nature 2007
18353650 Activating the ubiquitin family: UBA6 challenges the field

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

Trends Biochem. Sci. 2008
17580310 UBE1L2, a novel E1 enzyme specific for ubiquitin

Pelzer, C, Singh, RK, Groettrup, M, Scheffner, M, Matentzoglu, K, Schmidtke, G, Kassner, I, Wollscheid, HP

J. Biol. Chem. 2007
Catalyst Activity

ubiquitin activating enzyme activity of Ub-Cys625-UBA6 [cytosol]

Inferred From
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