Gamma-glutamylcyclotransferase (IPR017939)

Short name: G-Glutamylcylcotransferase

Overlapping homologous superfamilies

Family relationships



This entry contains the human protein C7orf24 (O75223) has been implicated as a cancer marker with a potential role in cell proliferation. It has been characterised as gamma-glutamyl cyclotransferase (GGCT), a homodimer of two 21 kDa subunits, that catalyses the formation of 5-oxoproline (2-pyrrolidone-5-carboxylic acid, pyroglutamic acid) from gamma-glutamyl dipeptides () [PMID: 18515354].

L-gamma-glutamyl-L-amino acid -> 5-oxoproline + L-amino acid

The structure of O75223 has been solved at 1.7 A resolution. The topology of GGCT is unrelated to other enzymes associated with cyclotransferase-like activity and its structure has been termed the GGCT-fold, which appears to be related to the BtrG-like superfamily. A potential active site pocket contains a highly conserved glutamic acid (Glu(98)), which when converted to either Ala or Gln completely inactivates the enzyme without altering the overall fold [PMID: 18515354].

This entry also includes GliK from fungi. It is part of the gene cluster that mediates the biosynthesis of gliotoxin, a member of the epipolythiodioxopiperazine (ETP) class of toxins characterised by a disulfide bridged cyclic dipeptide [PMID: 15979823, PMID: 21612254].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0003839 gamma-glutamylcyclotransferase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.