A NOVEL PROTEIN SECRETION FACTOR FROM A VIBRIO SPECIES WHICH OPERATESIN ESCHERICHIA-COLI

A DNA fragment specific to a Vibrio species was found to promote extra cellular secretion of proteins, when cloned into Escherichia coli. Cel ls harboring a plasmid carrying this fragment secreted significant amo unts of periplasmic beta-lactamase and alkaline phosphatase into the m edium, however most cytoplasmic beta-galactosidase was retained within the cell. The DNA sequence essential for this property was found to b e a gene encoding 76 amino acids, which was designated as the 'PAS fac tor'. Highly expressed PAS factor is harmful to the cell, this may be due to a disruption of the membrane structure and/or function.