CATH Classification

Domain Context

CATH Clusters

Superfamily Zinc/RING finger domain, C3HC4 (zinc finger)
Functional Family Baculoviral IAP repeat containing 2

Enzyme Information

2.3.2.27
RING-type E3 ubiquitin transferase.
based on mapping to UniProt P98170
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)

P98170
XIAP_HUMAN
Homo sapiens
E3 ubiquitin-protein ligase XIAP

PDB Structure

PDB 2ECG
External Links
Method SOLUTION NMR
Organism
Primary Citation
Solution structure of the ring domain of the Baculoviral IAP repeat-containing protein 4 from Homo sapiens
Miyamoto, K., Sato, M., Koshiba, S., Watanabe, S., Harada, T., Kigawa, T., Yokoyama, S.
To be Published