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
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 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 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 -!- Cf. EC

UniProtKB Entries (1)

Homo sapiens
E3 ubiquitin-protein ligase XIAP

PDB Structure

External Links
Organism Escherichia
Primary Citation
Discovery of Potent Antagonists of the Antiapoptotic Protein XIAP for the Treatment of Cancer.
Oost, T.K., Sun, C., Armstrong, R.C., Al-Assaad, A.S., Betz, S.F., Deckwerth, T.L., Ding, H., Elmore, S.W., Meadows, R.P., Olejniczak, E.T., Oleksijew, A., Oltersdorf, T., Rosenberg, S.H., Shoemaker, A.R., Tomaselli, K.J., Zou, H., Fesik, S.W.