Molecular cloning and nucleotide sequence of the cyclomaltodextrin glucanotransferase gene from the alkalophilic Bacillus sp. strain no. 38-2.

The cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) gene from the alkalophilic Bacillus sp. strain no. 38-2 was cloned in Escherichia coli using pBR322. A plasmid, pCS8, was isolated from a transformant producing CGTase and the cloned CGTase gene was found to be in a 5.3 kb DNA fragment. The nucleotide sequence of a 2.5 kb segment encoding the CGTase was determined. This segment showed an open reading frame which would encode a polypeptide of 712 amino acids. The pCS8 CGTase had the same enzymic properties as those of the extracellular CGTase produced by the alkalophilic Bacillus sp. strain no. 38-2. The nucleotide and amino acid sequences of this CGTase gene and gene product, respectively, have strong homology with those of the Bacillus macerans CGTase.