Reactome | E1 mediated ubiquitin activation

E1 mediated ubiquitin activation

Stable Identifier

R-HSA-983153

Type

Reaction [transition]

Species

Homo sapiens

Compartment

cytosol

ReviewStatus

5/5

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Ubiquitin is activated in an ATP-dependent manner, catalyzed by E1 ubiquitin-activating enzymes. In the first step of ubiquitin activation, the E1 enzyme binds ATP, Mg+2 and ubiquitin, and catalyses ubiquitin C-terminal acyl-adenylation (Ubiquitin-AMP). In the second step, the catalytic cystine in the E1 attacks the ubiquitin-adenylate (Ub-AMP) to form the activated ubiquitin-E1 thioester-bonded complex and an AMP leaving group. The intermediate reaction involving the formation of the ubiquitin-AMP complex is not represented here.

Literature References

PubMed ID	Title	Journal	Year
16595681	Pleiotropic effects of ATP.Mg2+ binding in the catalytic cycle of ubiquitin-activating enzyme Bohnsack, RN, Tokgöz, Z, Haas, AL	J Biol Chem	2006
19352404	Ubiquitin-like protein activation by E1 enzymes: the apex for downstream signalling pathways Schulman, BA, Harper, JW	Nat Rev Mol Cell Biol	2009
18662542	Structural insights into E1-catalyzed ubiquitin activation and transfer to conjugating enzymes Schindelin, H, Lee, I	Cell	2008