GGCT-like domains, also called AIG2-like family. Gamma-glutamyl cyclotransferase (GGCT) catalyzes the formation of pyroglutamic acid (5-oxoproline) from dipeptides containing gamma-glutamyl, and is a dimeric protein. In Homo sapiens, the protein is encoded by the gene C7orf24, and the enzyme participates in the gamma-glutamyl cycle. Hereditary defects in the gamma-glutamyl cycle have been described for some of the genes involved, but not for C7orf24. The synthesis and metabolism of glutathione (L-gamma-glutamyl-L-cysteinylglycine) ties the gamma-glutamyl cycle to numerous cellular processes; glutathione acts as a ubiquitous reducing agent in reductive mechanisms involved in protein and DNA synthesis, transport processes, enzyme activity, and metabolism. AIG2 (avrRpt2-induced gene) is an Arabidopsis protein that exhibits RPS2- and avrRpt2-dependent induction early after infection with Pseudomonas syringae pv maculicola strain ES4326 carrying avrRpt2. avrRpt2 is an avirulence gene that can convert virulent strains of P. syringae to avirulence on Arabidopsis thaliana, soybean, and bean. The family also includes bacterial tellurite-resistance proteins (trgB); tellurium (Te) compounds are used in industrial processes and had been used as antimicrobial agents in the past. Some members have been described proteins involved in cation transport (chaC).