EC Number   |
Substrates |
Organism |
Products |
Reversibility |
|---|
   2.3.2.24 | 2 N6-monoubiquitinyl-[Ubc1]-L-lysine |
- |
Saccharomyces cerevisiae |
N6-diubiquitinyl-[Ubc1]-L-lysine + [Ube2K]-L-lysine |
- |
? |
| 2.3.2.24 | 2 N6-monoubiquitinyl-[Ube2K]-L-lysine |
- |
Homo sapiens |
N6-diubiquitinyl-[Ube2K]-L-lysine + [Ube2K]-L-lysine |
- |
? |
| 2.3.2.24 | more |
beta-lactoglobulin and reduced carboxymethylated bovine serum albumin rcmBSA are not conjugates |
Oryctolagus cuniculus |
? |
- |
? |
| 2.3.2.24 | more |
polyubiquitin chain formation catalyzed by E2 enzymes, in the absence of an E3 protein and a target protein substrate |
Homo sapiens |
? |
a thiol ester-linked ubiquitin to the E2 active site is an intermediate in any polyubiquination reactions |
? |
| 2.3.2.24 | more |
the presence of ubiquitin-binding domains (UBDs) allows the ubiquitination of host proteins independently of E3 ligases. UBDs of different types, including ubiquitin-interacting motif UIM, ubiquitin-associated domain UBM, and ubiquitin-binding zinc finger domain UBZ, can directly cooperate with ubiquitin-charged E2 enzymes to promote monoubiquitination. Ubiquitin-loaded E2 and substrates interact in cells and E2 enzymes are essential for their monoubiquitination in vivo. This modification is mechanistically and functionally distinct from E3-mediated and growth factor-dependent monoubiquitination. The ability to transfer ubiquitin to a substrate is a common feature of all tested E2 enzymes. However, E2 enzymes show substrate specificity |
Homo sapiens |
? |
- |
? |
| 2.3.2.24 | more |
E3-independent ubiquitination by Ube2K produces unanchored but also Ube2K-linked polyubiquitins through thioester and isopeptide bonds. E3-independent assembly of polyubiquitins on the catalytic cysteine of Ube2K strongly supports the possibility of en bloc transfer for polyubiquitination. Different lengths of polyubiquitins are linked to different E2s through thioester bond. In vitro E3-independent ubiquitination by Ube2K simultaneously produces unanchored, isopeptde-linked, and thioester-linked polyubiquitin chains |
Homo sapiens |
? |
- |
? |
| 2.3.2.24 | more |
isoform UbcH10 does not preassemble polyubiquitin chains on its acitve site cysteine |
Homo sapiens |
? |
- |
? |
| 2.3.2.24 | more |
ubiquitin thiol ester forms of at least four of five E2s tested catalyze ubiquitin transfer to a number of small amines, in a reaction that does not require E3 enzyme, and only primary amines on primary carbons can serve as ubiquitin acceptors. E3-independent ubiquitin transfer to the small, basic proteins histones H2A and H2B, and cytochrome c, is also observed |
Homo sapiens |
? |
- |
? |
| 2.3.2.24 | more |
E2-EPF ubiquitin carrier protein (UCP) possesses E3 ubiquitin ligase activity via its cysteine 118 residue. E2-EPF UCP elongates E3-independent polyubiquitin chains on the lysine residues of von Hippel-Lindau protein (pVHL) and its own lysine residues both in vitro and in vivo. The initiation of the ubiquitin reaction depends on not only Lys11 linkage but also the Lys6, Lys48 and Lys63 residues of ubiquitin, which are involved in polyubiquitin chain formation on UCP itself. UCP self-association occurred through the UBC domain, which also contributes to the interaction with pVHL. The polyubiquitin chains appears on the N-terminus of UCP in vivo, which indicates that the N-terminus of UCP contains target lysines for polyubiquitination. The Lys76 residue of UCP is the most critical site for auto-ubiquitination, whereas the polyubiquitin chain formation on pVHL occurrs on all three of its lysines (Lys159, Lys171 and Lys196). Polyubiquitin chain formation requires the coordination of Cys95 and Cys118 between two interacting molecules. The mechanism of the polyubiquitin chain reaction of UCP may involve the transfer of ubiquitin from Cys95 to Cys118 by trans-thiolation, with polyubiquitin chains forming at Cys118 by reversible thioester bonding. The polyubiquitin chains are then moved to the lysine residues of the substrate by irreversible isopeptide bonding. During the elongation of the ubiquitin chain, an active Cys118 residue is required in both parts of UCP, namely, the catalytic enzyme and the substrate |
Homo sapiens |
? |
- |
- |
| 2.3.2.24 | more |
the enzyme interacts with E3 ligases of types RING and RBR, and with its own N-terminus |
Homo sapiens |
? |
- |
- |
