Transglutaminases, TGase, catalyse an acyl transfer reaction in which gamma-caboxyamide groups of the peptide-bound glutamine residues act as acyl donors with e-amino lysine groups as acyl acceptors. The microbial tranglutaminase, MTG, from Streptoverticllium mobaraense is Ca2+ independent unlike mammalian TGases and folds in to aplate-like shape with a deep cleft at the edge of the molecule. MTG is secreted from the cytoplasm and is activated by proteolytic processing. The additional pro-sequence consisting of 45 amino acid residues at the N terminus is cleaved off, resulting in the active form, the mature enzyme. Industrial applications of MTG include improving the physical and textural properties of protein-rich foods.
Defined by 4 residues: CYS:A-64ASP:A-255TRP:A-272HIS:A-274