Cloning and expression of the Bacillus amyloliquefaciens transglutaminase gene in E. coli using a bicistronic vector construction

[Display omitted] •Cloning and expression of recombinant B. amyloliquefaciens TGase in E. coli.•Protein was obtained in its soluble and active form.•A bicistronic plasmid was constructed to avoid host cells toxicity.•TGase gene was fused to the inhibitory S. caniferus prodomain.•We cloned the 3C protease gene into the same plasmid to avoid in vitro prodomain removal. Transglutaminases (TGases) are a class of transferases widely used in the food and biotechnology industries. In this work, we describe the production of recombinant Bacillus amyloliquefaciens TGase in Escherichia coli, obtaining the protein in its soluble and active form. In order to reduce TGase activity inside host cells and consequently its toxicity, we constructed a bicistronic plasmid containing the B. amyloliquefaciens TGase gene fused to the inhibitory Streptomyces caniferus prodomain. To make the enzyme active and avoid the need of prodomain removal in vitro, we also cloned the 3C protease gene into the same plasmid. After a fast single-step purification protocol, we obtained a partially purified recombinant TGase with 37 mU/mg protein activity, that crosslinked bovine serum albumin (BSA). This is the first report on the expression of B. amyloliquefaciens TGase in E. coli in its mature and active form.