Abstract The gene for an alkaline protease, suitable for use in both powder and liquid detergents, from the alkalophilic Bacillus sp. KSM-K16 was cloned and sequenced. Its nucleotide sequence included an open reading frame of 1,143 bp (380 amino acids) that encoded a pre-pro-peptide (111 amino acids) and a mature protein (269 amino acids, 26,723 Da). The deduced amino acid sequence of the enzyme exhibited high homology to those of alkaline proteases from alkalophilic strains of Bacillus and moderate homology to those of subtilisins reported to date. The catalytic triad (Asp32, His64 and Ser221) and the subsite sequence (Ser125-Leu126-Gly127) of subtilisin BPN′ were well conserved as Asp32, His62 and Ser215 and as Ser123-Leu124-Gly125, respectively. However, the third (“wobble”) positions of sense codons revealed some marked differences between our protease and subtilisins (and related alkaline proteases).