BACILLUS-LICHENIFORMIS MC14 ALKALINE-PHOSPHATASE-I GENE WITH AN EXTENDED COOH-TERMINUS

Bacterial alkaline phosphatases (APases), except those isolated from B acillus licheniformis, are approximately 45-kDa proteins while eucaryo tic alkaline phosphatases are 60 kDa. To answer the question of whethe r the apparent 60-kDa alkaline phosphatase from Bacillus licheniformis accurately reflected the size of the protein, the entire gene was ana lyzed, DNA sequence analysis of the alkaline phosphatase I (APaseI) ge ne of B. licheniformis MC14 indicated that the gene could code for a 6 0-kDa protein of 553 amino acids. The deduced protein sequence of APas eI showed about 32% identity to those of B. subtilis APase III and IV and had apparent sequence homologies in the core structure and active sites that are conserved among APases of various sources. The extra ca rboxy-terminal sequence of APaseI, which made the enzyme bigger than o ther procaryotic APases, was not homologous to those of eucaryotic APa ses, The amino acid composition of APaseI was most similar to that of salt-dependent APase among the isozymes of B. licheniformis MC14. Anot her open reading frame of 261 amino acids was present 142 nucleotide u pstream of the APaseI gene and its predicted amino acid sequence showe d 68% identity to that of glucose dehydrogenase of B. megaterium. (C) 1998 Federation of European Microbiological Societies. Published by El sevier Science B.V.