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)

Q5X159
LUBX_LEGPA
Legionella pneumophila str. Paris
E3 ubiquitin-protein ligase LubX
P62837
UB2D2_HUMAN
Homo sapiens
Ubiquitin-conjugating enzyme E2 D2

PDB Structure

PDB 4WZ3
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Molecular Characterization of LubX: Functional Divergence of the U-Box Fold by Legionella pneumophila.
Quaile, A.T., Urbanus, M.L., Stogios, P.J., Nocek, B., Skarina, T., Ensminger, A.W., Savchenko, A.
Structure