Microbial transglutaminase (MTG) catalyses an acyl transfer reaction by means of a Cys-Asp diad mechanism, in which the gamma-carboxyamide groups of peptide-bound glutamine residues act as the acyl donors. The MTG molecule forms a single, compact dom ...
Microbial transglutaminase (MTG) catalyses an acyl transfer reaction by means of a Cys-Asp diad mechanism, in which the gamma-carboxyamide groups of peptide-bound glutamine residues act as the acyl donors. The MTG molecule forms a single, compact domain belonging to the alpha+beta folding class, containing 11 alpha-helices and 8 beta-strands. The alpha-helices and the beta-strands are concentrated mainly at the amino and carboxyl ends of the polypeptide, respectively. These secondary structures are arranged so that a beta-sheet is surrounded by alpha-helices, which are clustered into three regions [1].
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
