Accepted name: ubiquitinyl hydrolase 1
Reaction: 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)
Other name(s): ubiquitin C-terminal hydrolase; yeast ubiquitin hydrolase
Comments: Links to polypeptides smaller than 60 residues are hydrolysed more readily than those to larger polypeptides. Isoforms exist with quantitatively different specificities, amongst the best known being UCH-L1 and UCH-L3, which are major proteins of the brain of mammals [1]. Inhibited by ubiquitin aldehyde (in which Gly76 is replaced by aminoacetaldehyde). Ubiquitinyl hydrolase 1 is the type example of peptidase family C12, with a similar protein fold to papain and catalytic amino acids Cys, His and Asp. There is a separate family (C19) of enzymes that also hydrolyse ubiquitinyl bonds, and it is thought that all the ubiquitinyl hydrolases are also ubiquitin thiolesterases (EC
1.  Johnston, S.C., Larsen, C.N., Cook, W.J., Wilkinson, K.D. and Hill, C.P. Crystal structure of a deubiquitinating enzyme (human UCH-L3) at 1.8Å resolution. EMBO J. 16 (1997) 3787–3796. [PMID: 9233788]
2.  Wilkinson, K.D. Ubiquitin C-terminal hydrolase. In: Barrett, A.J., Rawlings, N.D. and Woessner, J.F. (Ed.), Handbook of Proteolytic Enzymes, Academic Press, London, 1998, pp. 470–472.
[EC created 2000]