CATH Classification

Domain Context

CATH Clusters

Superfamily Ubiquitin Conjugating Enzyme
Functional Family Ubiquitin-conjugating enzyme E2 D2

Enzyme Information

2.3.2.24
(E3-independent) E2 ubiquitin-conjugating enzyme.
based on mapping to UniProt P62837
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.
2.3.2.23
E2 ubiquitin-conjugating enzyme.
based on mapping to UniProt P62837
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.

UniProtKB Entries (2)

Q9XVR6
OTUBL_CAEEL
Caenorhabditis elegans
Ubiquitin thioesterase otubain-like
P0CG48
UBC_HUMAN
Homo sapiens
Polyubiquitin-C

PDB Structure

PDB 4LDT
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
E2 ubiquitin-conjugating enzymes regulate the deubiquitinating activity of OTUB1.
Wiener, R., Dibello, A.T., Lombardi, P.M., Guzzo, C.M., Zhang, X., Matunis, M.J., Wolberger, C.
Nat.Struct.Mol.Biol.