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.
3.4.19.12
Ubiquitinyl hydrolase 1.
based on mapping to UniProt Q96FW1
Thiol-dependent hydrolysis of ester, thioester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal).
-!- Links to polypeptides smaller than 60 residues are hydrolyzed more readily than those to larger polypeptides. -!- Isoforms exist with quantitatively different specificities among the best known being UCH-L1 and UCH-L3, major proteins of the brain of mammals. -!- Inhibited by ubiquitin aldehyde (in which Gly76 is replaced by aminoacetaldehyde). -!- Belongs to peptidase family C12.

UniProtKB Entries (1)

Q96FW1
OTUB1_HUMAN
Homo sapiens
Ubiquitin thioesterase OTUB1

PDB Structure

PDB 4DDI
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
OTUB1 Co-opts Lys48-Linked Ubiquitin Recognition to Suppress E2 Enzyme Function.
Juang, Y.C., Landry, M.C., Sanches, M., Vittal, V., Leung, C.C., Ceccarelli, D.F., Mateo, A.R., Pruneda, J.N., Mao, D.Y., Szilard, R.K., Orlicky, S., Munro, M., Brzovic, P.S., Klevit, R.E., Sicheri, F., Durocher, D.
Mol.Cell