CLONING AND NUCLEOTIDE-SEQUENCE OF THE ALPHA-AMYLASE GENE FROM ALKALOPHILIC PSEUDOMONAS SP KFCC-10818

A gene coding for a new amylolytic enzyme from Pseudomonas sp. KFCC 10 818 was cloned, and its nucleotide sequence was determined. Starting f rom an ATG initiation codon, there was an open reading frame composed of 1,398 bases in the sequence. A deduced amino acid sequence containe d four highly conserved regions of alpha-amylases. Cloned amylase was purified from Escherichia coli, NH2-terminal sequencing of the enzyme showed the presence of a signal peptide composed of 23 amino acids. Ma ltose and maltotriose were major end products from starch by the enzym e action. pH and temperature optima of the alpha-amylase were pH 8 and 45 degrees C, respectively. The enzyme kept almost all catalytic acti vity during 3 h incubation between pH 7-11.