CATH Classification
| Level | CATH Code | Description |
|---|---|---|
|
3 | Alpha Beta |
|
3.10 | Roll |
|
3.10.110 | Ubiquitin Conjugating Enzyme |
|
3.10.110.10 | Ubiquitin Conjugating Enzyme |
Domain Context
CATH Clusters
| Superfamily | Ubiquitin Conjugating Enzyme |
| Functional Family | Ubiquitin-conjugating enzyme E2 D2 |
Enzyme Information
| 2.3.2.23 |
E2 ubiquitin-conjugating enzyme.
based on mapping to UniProt P61077
S-ubiquitinyl-[E1 ubiquitin-activating enzyme]-L-cysteine + [E2 ubiquitin-conjugating enzyme]-L-cysteine = [E1 ubiquitin-activating enzyme]-L-cysteine + S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L- cysteine.
-!- The E2 ubiquitin-conjugating enzyme acquires the activated ubquitin from the E1 ubiquitin-activating enzyme (EC 6.2.1.45) and binds it via a transthioesterification reaction to itself. -!- In the human enzyme the catalytic center is located at Cys-87 where ubiquitin is bound via its C-terminal glycine in a thioester linkage. -!- Formerly EC 6.3.2.19.
|
| 2.3.2.24 |
(E3-independent) E2 ubiquitin-conjugating enzyme.
based on mapping to UniProt P61077
S-ubiquitinyl-[E1 ubiquitin-activating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E1 ubiquitin-activating enzyme]-L-cysteine + N(6)- monoubiquitinyl-[acceptor protein]-L-lysine.
-!- The enzyme transfers a single ubiquitin directly from an ubiquitinated E1 ubiquitin-activating enzyme to itself, and on to a lysine residue of the acceptor protein without involvement of E3 ubiquitin transferases (cf. EC 2.3.2.26, EC 2.3.2.27). -!- It forms a labile ubiquitin adduct in the presence of E1, ubiquitin, and Mg(2+)-ATP and catalyzes the conjugation of ubiquitin to protein substrates, independently of E3. -!- This transfer has only been observed with small proteins. -!- In vitro a transfer to small acceptors (e.g. L-lysine, N-acetyl-L- lysine methyl ester) has been observed.
|
UniProtKB Entries (1)
| O95155 |
UBE4B_HUMAN
Homo sapiens
Ubiquitin conjugation factor E4 B
|
PDB Structure
| PDB | 3L1Z |
| External Links | |
| Method | X-RAY DIFFRACTION |
| Organism | |
| Primary Citation |
Molecular Basis for the Association of Human E4B U Box Ubiquitin Ligase with E2-Conjugating Enzymes UbcH5c and Ubc4.
Structure
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