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 | 
Enzyme Information
| 2.3.2.23 | 
							 E2 ubiquitin-conjugating enzyme. 
							based on mapping to UniProt P51668 		
							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 P51668 		
							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 (2)
| O88846 | 
						 RNF4_RAT 
						Rattus norvegicus 
						E3 ubiquitin-protein ligase RNF4 
					 | 
				
| P51668 | 
						 UB2D1_HUMAN 
						Homo sapiens 
						Ubiquitin-conjugating enzyme E2 D1 
					 | 
				
PDB Structure
| PDB | 4AP4 | 
| External Links | |
| Method | X-RAY DIFFRACTION | 
| Organism | |
| Primary Citation | 
					 Structure of a Ring E3 Ligase and Ubiquitin-Loaded E2 Primed for Catalysis 
					    
					    Nature 
					    
					 | 
			
