title: Cloning of the beta-amylase gene from Bacillus cereus and characteristics of the primary structure of the enzyme.
abstract: The gene encoding the beta-amylase of Bacillus cereus BQ10-S1 (SpoII) was cloned into Escherichia coli JM 109. A sequenced DNA fragment of 2,001 bp contains the beta-amylase gene. The N-terminal sequences (AVNGKG MNPDYKAYLMAPLKKI), the C-terminal sequences (SHTSSW), and the amino acid sequences of the five regions in the beta-amylase molecules were determined. The mature beta-amylase contains 514 amino acid residues with a molecular mass of 57,885 Da. The amino acid sequence homology with those of known beta-amylases was 52.7% for Bacillus polymyxa, 52.0% for Bacillus circulans, 43.4% for Clostridium thermosulfurogenes, 31.8% for Arabidopsis thaliana, 31.5% for barley, 29.9% for sweet potato, and 28.9% for soybean. Ten well-conserved regions were found between the N terminus and the area around residue 430, but the C-terminal region of 90 residues has no similarity with those of the plant beta-amylases. The homology search revealed that this C-terminal region has homology with C-terminal regions of the beta-amylase from C. thermosulfurogenes, some bacterial alpha-amylases, cyclodextrin glucanotransferase, and glucoamylase. Some of these sequences are known as the raw-starch-binding domain. These results suggest that B. cereus beta-amylase has an extra domain which has raw-starch-binding ability and that the domain has considerable sequence homology with those of other amylases or related enzymes from a wide variety of microorganisms.
authors.affiliation: Department of Agricultural Chemistry, Faculty of Agriculture, Kobe University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nanmori
authors.forename: M
authors.initials: M
authors.lastname: Nagai
authors.forename: Y
authors.initials: Y
authors.lastname: Shimizu
authors.forename: R
authors.initials: R
authors.lastname: Shinke
authors.forename: B
authors.initials: B
authors.lastname: Mikami
mesh_terms: D000595:Amino Acid Sequence; D001409:Bacillus cereus / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics*; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D001614:beta-Amylase / Q000737:chemistry* / Q000235:genetics
chemical_list: D001614:beta-Amylase