X-ray diffraction
3.4Å resolution

Structure of the cIAP2 RING domain bound to UbcH5b


Function and Biology Details

Reactions catalysed:
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
S-ubiquitinyl-[E1 ubiquitin-activating enzyme]-L-cysteine + [E2 ubiquitin-conjugating enzyme]-L-cysteine = [E1 ubiquitin-activating enzyme]-L-cysteine + S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine
(1a) S-ubiquitinyl-[E1 ubiquitin-activating enzyme]-L-cysteine + [(E3-independent) E2 ubiquitin-conjugating enzyme]-L-cysteine = [E1 ubiquitin-activating enzyme]-L-cysteine + S-monoubiquitinyl-[(E3-independent) ubiquitin-conjugating enzyme]-L-cysteine
Biochemical function:
Biological process:
Cellular component:
  • not assigned

Structure analysis Details

Assembly composition:
hetero tetramer (preferred)
Entry contents:
2 distinct polypeptide molecules
Macromolecules (2 distinct):
Baculoviral IAP repeat-containing protein 3 Chain: A
Molecule details ›
Chain: A
Length: 74 amino acids
Theoretical weight: 8.24 KDa
Source organism: Homo sapiens
Expression system: Escherichia coli
  • Canonical: Q13489 (Residues: 536-604; Coverage: 11%)
Gene names: API2, BIRC3, MIHC, RNF49
Sequence domains: Zinc finger, C3HC4 type (RING finger)
Structure domains: Zinc/RING finger domain, C3HC4 (zinc finger)
Ubiquitin-conjugating enzyme E2 D2 Chain: B
Molecule details ›
Chain: B
Length: 149 amino acids
Theoretical weight: 16.9 KDa
Source organism: Xenopus laevis
Expression system: Escherichia coli
  • Canonical: P62840 (Residues: 1-147; Coverage: 100%)
Gene names: ubc4, ube2d2, ube2d3.1
Sequence domains: Ubiquitin-conjugating enzyme
Structure domains: Ubiquitin Conjugating Enzyme

Ligands and Environments

1 bound ligand:

No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: RIGAKU MICROMAX-007
Spacegroup: P6322
Unit cell:
a: 137.226Å b: 137.226Å c: 111.87Å
α: 90° β: 90° γ: 120°
R R work R free
0.283 0.281 0.32
Expression system: Escherichia coli