PROSITE documentation PDOC01036
Pyrrolidone-carboxylate peptidase active sites


Pyrrolidone-carboxylate peptidase (EC (PYRase) (also known as pyroglutamyl peptidase) is the enzyme that selectively removes pyroglutamate (pGlu) from the N-terminus of proteins and peptides.

In bacteria and archebacteria PYRase (gene pcp) is a protein of 22-25 kD. It is a cysteine protease with a Cys-His-Glu catalytic triad [1,2]. We developed two signature patterns that respectively include the glutamate and cysteine active site residues.


These proteins belong to family C15 in the classification of peptidases [3,E1].

Last update:

December 2004 / Pattern and text revised.


Technical section

PROSITE methods (with tools and information) covered by this documentation:

PYRASE_CYS, PS01334; Pyrrolidone-carboxylate peptidase cysteine active site  (PATTERN)

PYRASE_GLU, PS01333; Pyrrolidone-carboxylate peptidase glutamic acid active site  (PATTERN)


1AuthorsSingleton M.R. Isupov M. Littlechild J.
TitleX-ray structure of pyrrolidone carboxyl peptidase from the hyperthermophilic archaeon Thermococcus litoralis.
SourceStructure 7:237-244(1999).
PubMed ID10368293

2AuthorsOdagaki Y. Hayashi A. Okada K. Hirotsu K. Kabashima T. Ito K. Yoshimoto T. Tsuru D. Sato M. Clardy J.
TitleThe crystal structure of pyroglutamyl peptidase I from Bacillus amyloliquefaciens reveals a new structure for a cysteine protease.
SourceStructure 7:399-411(1999).
PubMed ID10196127

3AuthorsRawlings N.D. Barrett A.J.
TitleFamilies of cysteine peptidases.
SourceMethods Enzymol. 244:461-486(1994).
PubMed ID7845226


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