CATH Classification

Domain Context

CATH Clusters

Superfamily Zinc/RING finger domain, C3HC4 (zinc finger)
Functional Family ubiquitin conjugation factor E4 B

Enzyme Information

2.3.2.27
RING-type E3 ubiquitin transferase.
based on mapping to UniProt O95155
S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)- ubiquitinyl-[acceptor protein]-L-lysine.
-!- RING E3 ubiquitin transferases serve as mediators bringing the ubiquitin-charged E2 ubiquitin-conjugating enzyme (EC 2.3.2.23) and an acceptor protein together to enable the direct transfer of ubiquitin through the formation of an isopeptide bond between the C-terminal glycine residue of ubiquitin and the epsilon-amino group of an L-lysine residue of the acceptor protein. -!- Unlike EC 2.3.2.26 the RING-E3 domain does not form a catalytic thioester intermediate with ubiquitin. -!- Many members of the RING-type E3 ubiquitin transferase family are not able to bind a substrate directly, and form a complex with a cullin scaffold protein and a substrate recognition module (the complexes are named CRL for Cullin-RING-Ligase). -!- In these complexes, the RING-type E3 ubiquitin transferase provides an additional function, mediating the transfer of a NEDD8 protein from a dedicated E2 carrier to the cullin protein (see EC 2.3.2.32). -!- Cf. EC 2.3.2.31.

UniProtKB Entries (1)

O95155
UBE4B_HUMAN
Homo sapiens
Ubiquitin conjugation factor E4 B

PDB Structure

PDB 3L1X
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Molecular Basis for the Association of Human E4B U Box Ubiquitin Ligase with E2-Conjugating Enzymes UbcH5c and Ubc4.
Benirschke, R.C., Thompson, J.R., Nomine, Y., Wasielewski, E., Juranic, N., Macura, S., Hatakeyama, S., Nakayama, K.I., Botuyan, M.V., Mer, G.
Structure