Protein secretion inBacillus subtilisas influenced by the combination of signal sequence and the following mature portion

We have constructed secretion vector plasmids that have the signal sequence of the Bacillus licheniformis penicillinase gene (penP) or the Bacillus stearothermophilusα-amylase gene (amyT). We have also constructed penP, amyT and hsa (human salivary α-amylase gene) cartridges. Each of these cartridges was cloned on secretion vectors in Bacillus subtilis, and enzyme production was examined. When amyT vector was used, nearly the same efficiency of enzyme secretion was observed for amyT and penP cartridges. When penP vector was used, enzyme secretion for amyT decreased to about 3% of that for penP cartridges. The eukaryotic gene hsa was hardly expressed in any secretion vectors in B. subtilis.