Figure 23.3. Ubiquitin Conjugation.

Figure 23.3Ubiquitin Conjugation

The ubiquitin-activating enzyme E1 adenylates ubiquitin (Ub) and transfers the ubiquitin to one of its own cysteine residues. Ubiquitin is then transferred to a cysteine residue in the ubiquitin-conjugating enzyme E2. Finally, the ubiquitin-protein ligase E3 transfers the ubiquitin to a lysine residue onthe target protein.

From: Section 23.2, Protein Turnover Is Tightly Regulated

Cover of Biochemistry
Biochemistry. 5th edition.
Berg JM, Tymoczko JL, Stryer L.
New York: W H Freeman; 2002.
Copyright © 2002, W. H. Freeman and Company.

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