Structural elements responsible for transglutaminase activity of protein disulphide isomerases and thioredoxins
Blaskó, B.; Mádi, A.; Fésüs, L.
Journal of Biological Regulators and Homeostatic Agents 18(1): 1-8
2004
ISSN/ISBN: 0393-974X PMID: 15323354 Document Number: 570765
According to recent results both protein disulphide isomerase (PDI) and thioredoxin (Trx) enzymes have transglutaminase activity which can be linked to the thioredoxin box found in these proteins. Analysis of known protein disulphide isomerase and thioredoxin sequences has revealed the presence of conserved Cys, His and Asp residues required for transglutaminases to catalyze the incorporation of primary amines into protein-bound glutamine residues. The available 3D structures of PDIs and Trxs show that these residues are in close proximity to achieve transglutamylation of substrate proteins. The shared activities of the members of the large protein disulphide isomerase, thioredoxin and transglutaminase enzyme families reviewed here may have general biological significance in the regulation of cellular and tissue processes.