CATH Classification

Domain Context

CATH Clusters

Superfamily main proteinase (3clpro) structure, domain 3
Functional Family Replicase polyprotein 1a

Enzyme Information

3.4.22.-
Cysteine endopeptidases.
based on mapping to UniProt Q6RCY8
3.4.19.12
Ubiquitinyl hydrolase 1.
based on mapping to UniProt Q6RCY8
Thiol-dependent hydrolysis of ester, thioester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal).
-!- Links to polypeptides smaller than 60 residues are hydrolyzed more readily than those to larger polypeptides. -!- Isoforms exist with quantitatively different specificities among the best known being UCH-L1 and UCH-L3, major proteins of the brain of mammals. -!- Inhibited by ubiquitin aldehyde (in which Gly76 is replaced by aminoacetaldehyde). -!- Belongs to peptidase family C12.
3.4.22.69
SARS coronavirus main proteinase.
based on mapping to UniProt Q6RCY8
TSAVLQ-|-SGFRK-NH(2) and SGVTFQ-|-GKFKK the two peptides corresponding to the two self-cleavage sites of the SARS 3C-like proteinase are the two most reactive peptide substrates. The enzyme exhibits a strong preference for substrates containing Gln at P1 position and Leu at P2 position.
-!- SARS coronavirus main protease is the key enzyme in SARS coronavirus replicase polyprotein processing. -!- Belongs to peptidase family C30.

UniProtKB Entries (1)

Q6RCY8
Q6RCY8_CVHSA
SARS coronavirus TW7
Orf1a polyprotein

PDB Structure

PDB 2GZ9
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Structure-Based Drug Design and Structural Biology Study of Novel Nonpeptide Inhibitors of Severe Acute Respiratory Syndrome Coronavirus Main Protease
Lu, I.L., Mahindroo, N., Liang, P.H., Peng, Y.H., Kuo, C.J., Tsai, K.C., Hsieh, H.P., Chao, Y.S., Wu, S.Y.
J.Med.Chem.
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