CLONING AND SEQUENCE-ANALYSIS OF A PROTEASE-ENCODING GENE FROM THE MARINE BACTERIUM ALTEROMONAS SP STRAIN-0-7

The gene (aprI) encoding alkaline serine protease (AprI; subtilase) fr om Alteromonas sp. strain O-7 was cloned and sequenced. The nucleotide sequence of aprI has been identified. The deduced amino acid sequence indicated that aprI codes for a precursor of 715 amino acids and the precursor is composed of four regions including a signal peptide, an N -terminal pro-region, a mature protease region and a C-terminal extens ion region of 215 amino acids as previously described for aprII [H. Ts ujibo et al., Gene, 136, 247-251 (1993)]. The amino acid sequence of t he mature AprI (AprI-M) showed high sequence homology with those of ot her class I subtilases. The C-terminal region was characterized by a r epeat of 94 amino acids residues, which showed about 50% similarity wi th those of the C-terminal pro-region of several known proteases from Gram-negative bacteria.