CATH Classification

Domain Context

CATH Clusters

Superfamily Zinc/RING finger domain, C3HC4 (zinc finger)
Functional Family E3 ubiquitin-protein ligase

Enzyme Information

2.3.2.27
RING-type E3 ubiquitin transferase.
based on mapping to UniProt P61092
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)

P61092
SIA1A_MOUSE
Mus musculus
E3 ubiquitin-protein ligase SIAH1A

PDB Structure

PDB 2AN6
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Elucidation of the substrate binding site of Siah ubiquitin ligase
House, C.M., Hancock, N.C., Moller, A., Cromer, B.A., Fedorov, V., Bowtell, D.D.L., Parker, M.W., Polekhina, G.
Structure