EC Number   |
Substrates |
Products |
Reversibility |
|---|
   2.3.2.23 | more |
polyubiquitin chain formation catalyzed by E2 enzymes, in the absence of an E3 protein and a target protein substrate |
? |
a thiol ester-linked ubiquitin to the E2 active site is an intermediate in any polyubiquination reactions |
? |
| 2.3.2.23 | more |
kinetics for Uba1a-catalyzed transthiolation of Ubc2b are used as a reporter assay for determining the Km and kcat values for the three cosubstrates of the ubiquitin-activating enzyme. The E2 transthiolation assays are more sensitive to the potential presence of trace catalytically active fragments than the single turnover end point assays used for quantitating ternary complex stoichiometry |
? |
- |
? |
| 2.3.2.23 | more |
functional survey of 11 representative human E2 paralogs reveals similar Km values for binding to human Uba1 ternary complex with an average Km of 121 nM and kcat for ubiquitin transfer of 4.0 per s, suggesting that they possess a conserved binding site and transition state geometry and that they compete for charging through differences in intracellular concentration. This binding motif is localized to three basic residues within Helix 1 of the E2 core domain |
? |
- |
? |
| 2.3.2.23 | more |
HECT-E3 ligase ETC-1 ubiquitylates securin IFY-1 and cyclin B1 in the presence of the E2 enzyme UBC-18 |
? |
- |
? |
| 2.3.2.23 | more |
during transfer of ubiquitin to the final substrate or E3 ligase, reaction of EC 2.3.2.27, enzyme is restricted to monoubiquitinylation. UbcM2 shows enhanced polyubiquitin synthesizing activity in reaction mixtures containing ubiquitin mutant K48R. In contrast, reaction mixtures containing ubiquitin mutant K6R show a mild suppression of UbcM2 activity |
? |
- |
? |
| 2.3.2.23 | more |
human liver endoplasmic reticulum-anchored cytochrome P450 enzyme CYP3A4 is degraded via ubiquitylation by E2 ubiquitin-conjugating enzyme UBC7/E3 ubiquitin-ligase gp78, reaction of EC 2.3.2.27. CYP3A4 Asp/Glu/Ser(P)/Thr(P) surface clusters are important for its intermolecular electrostatic interactions with each of these E2-E3 subcomponents. By imparting additional negative charge to these Asp/Glu clusters, such Ser/Thr phosphorylation would generate P450 phosphodegrons for molecular recognition by the E2-E3 complexes, thereby controlling the timing of CYP3A4 ubiquitination and endoplasmic reticulum-associated degradation |
? |
- |
? |
| 2.3.2.23 | more |
the enzyme is nonreactive with free lysine |
? |
- |
? |
| 2.3.2.23 | more |
the enzyme interacts with ubiquitin, and E3 ligases of types RING, HECT, and RBR |
? |
- |
? |
| 2.3.2.23 | more |
the enzyme interacts with E3 ligases of types RING, HECT, and RBR, but not with ubiquitin |
? |
- |
? |
| 2.3.2.23 | more |
the enzyme interacts with ubiquitin, and E3 ligases of types RING, HECT, and RBR. Backside binding by Ub increases the intrinsic lysine reactivity of Ube2D2-Ub, indicating an allosteric effect |
? |
- |
? |
