USE OF A GRAM- SIGNAL PEPTIDE FOR PROTEIN SECRETION BY GRAM- BASIC PROTEASE OF DICHELOBACTER-NODOSUS IS PRODUCED AND SECRETED BY BACILLUS-SUBTILIS( HOSTS )

The bprV gene, encoding the extracellular basic protease of the Gram- anaerobic bacterium Dichelobacter nodosus, was expressed and the prote in secreted in Bacillus subtilis using the novel cloning/expression ve ctor pNC3 [Wu et al., Gene 106 (1991) 103-107]. The pre- and pro-pepti des were processed correctly in this heterologous system, and the 127- amino acid C-terminal extension region was also removed. The recombina nt gene product was indistinguishable biochemically or immunochemicall y from the authentic protease and was able to form crystals upon dialy sis, as was found for the authentic protease. This is the first exampl e of the direct secretion of a Gram- extracellular enzyme in B. subtil is via its own signal peptide. The fact that this gene can be expresse d and its product secreted in both Escherichia coli and B. subtilis pr ovides a unique opportunity to study and compare the similarities and differences in protein secretion between Gram- and Gram+ organisms.