CHARACTERIZATION OF AN ALKALINE SERINE-PROTEASE FROM AN ALKALINE-RESISTANT PSEUDOMONAS SP - CLONING AND EXPRESSION OF THE PROTEASE GENE IN ESCHERICHIA-COLI

A gene, aprP, encoding an extracellular alkaline serine protease from a newly isolated Pseudomonas sp. KFCC 10818 was cloned and characteriz ed. Nucleotide sequence analysis revealed an open reading frame of 1,2 66 nucleotides which could encode a polypeptide comprised of 422 amino acids. The C-terminal 283 residues showed an overall sequence homolog y with the subtilisin-type serine proteases. When expressed in E. coli , the alkaline protease, AprP, was released to the culture medium. The purified AprP was most active at pH 11. The k(cat)/K-m value of this enzyme was 9.2 x 10(3)S(-1)mM(-1), which is much higher than those of subtilisins.