Fusion of pro region of subtilisin to staphylococcal protein A and its secretion by Bacillus subtilis.

Subtilisin is synthesized as a preproenzyme in Bacillus subtilis. We fused that region of the subtilisin gene, (apr[BamP]), which encodes the signal sequence and pro region, to the mature gene sequence (spa) for a heterologous protein (staphylococcal protein A). B. subtilis cells harboring this gene fusion synthesized a fusion protein consisting of the signal and pro sequence of subtilisin fused to the protein A; the signal sequence was processed and a fusion protein (pro + protein A) was secreted into the growth medium.