Molecular cloning of an amylase gene of Bacillus circulans

An amylase gene of Bacillus circulans was cloned in B. subtilis and its nucleotide sequence was determined. The putative proamylase consists of 528 amino acids, which correspond to a molecular weight of 58,776. Homologous regions with other amylases of Bacillus species were found. A sigma 55-type promoter is located at about 250 bp upstream from the starting codon. This promoter was also functional in Escherichia coli, and able to express beta-galactosidase activity.