Molecular cloning and characterization of an extracellular protease gene from Aeromonas hydrophila

A structural gene which codes for an extracellular protease in Aeromonas hydrophilia SO2/2 and D13 was cloned in Escherichia coli C600-1 by using pBR322 as a vector. The gene codes for a temperature-stable protease with a molecular mass of approximately 38,000 daltons. The protein was secreted to the periplasm of E. coli C600-1 and purified by osmotic shock. Cloned protease (P3) was identical in molecular mass and properties to the one purified from A. hydrophila SO2/2 culture supernatant as an extracellular product.