CATH Domain 5ifrA00

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)

P0CG47

UBB_HUMAN

Homo sapiens

Polyubiquitin-B

PDB Structure

PDB	5IFR
External Links	PDBSum Proteopedia
Method	X-RAY DIFFRACTION
Organism
Primary Citation	A cascading activity-based probe sequentially targets E1-E2-E3 ubiquitin enzymes. Mulder, M.P., Witting, K., Berlin, I., Pruneda, J.N., Wu, K.P., Chang, J.G., Merkx, R., Bialas, J., Groettrup, M., Vertegaal, A.C., Schulman, B.A., Komander, D., Neefjes, J., El Oualid, F., Ovaa, H. Nat.Chem.Biol.