CATH Classification

Domain Context

CATH Clusters

Superfamily 3.40.50.1460
Functional Family Caspase-3 preproprotein

Enzyme Information

3.4.22.56
Caspase-3.
based on mapping to UniProt P42574
Strict requirement for an Asp residue at positions P1 and P4. It has a preferred cleavage sequence of Asp-Xaa-Xaa-Asp-|- with a hydrophobic amino-acid residue at P2 and a hydrophilic amino-acid residue at P3, although Val or Ala are also accepted at this position.
-!- Caspase-3 is an effector/executioner caspase, as are caspase-6 (EC 3.4.22.59) and caspase-7 (EC 3.4.22.60). -!- These caspases are responsible for the proteolysis of the majority of cellular polypeptides, (e.g. poly(ADP-ribose) polymerase (PARP)), which leads to the apoptotic phenotype. -!- Procaspase-3 can be activated by caspase-1 (EC 3.4.22.36), caspase-8 (EC 3.4.22.61), caspase-9 (EC 3.4.22.62) and caspase-10 (EC 3.4.22.63) as well as by the serine protease granzyme B. -!- Caspase-3 can activate procaspase-2 (EC 3.4.22.55). -!- Activation occurs by inter-domain cleavage followed by removal of the N-terminal prodomain. -!- While Asp-Glu-(Val/Ile)-Asp is thought to be the preferred cleavage sequence, the enzyme can accommodate different residues at P2 and P3 of the substrate. -!- Like caspase-2, a hydrophobic residue at P5 of caspase-3 leads to more efficient hydrolysis, e.g. (Val/Leu)-Asp-Val-Ala-Asp-|- is a better substrate than Asp-Val-Ala-Asp-|-. -!- This is not the case for caspase-7. -!- Belongs to peptidase family C14.

UniProtKB Entries (1)

P42574
CASP3_HUMAN
Homo sapiens
Caspase-3

PDB Structure

PDB 1QX3
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Conformational restrictions in the active site of unliganded human caspase-3
Ni, C.-Z., Li, C., Wu, J.C., Spada, A.P., Ely, K.R.
J.MOL.RECOG.