CATH Classification

Domain Context

CATH Clusters

Superfamily Inhibitor Of Apoptosis Protein (2mihbC-IAP-1); Chain A
Functional Family E3 ubiquitin-protein ligase XIAP

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 4OXC
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
NF023 binding to XIAP-BIR1: Searching drugs for regulation of the NF-kappa B pathway.
Cossu, F., Milani, M., Grassi, S., Malvezzi, F., Corti, A., Bolognesi, M., Mastrangelo, E.
Proteins