Lacks catalytic activity due to its inability to undergo the autocatalytic cleavage needed to produce a mature, enzymatically active heterodimer. Lacks catalytic activity due to its inability to undergo the autocatalytic cleavage needed to produce a mature, enzymatically active heterodimer. Lacks catalytic activity due to its inability to undergo the autocatalytic cleavage needed to produce a mature, enzymatically active heterodimer. Co-localizes with calnexin in the endoplasmic reticulum. Highly expressed in fetal and adult kidney and liver. Not cleaved by autocatalysis into a large and a small subunit resulting in loss of cell membrane localization and catalytic activity. Belongs to the gamma-glutamyltransferase family.