title: Construction of a chimeric series of Bacillus cyclomaltodextrin glucanotransferases and analysis of the thermal stabilities and pH optima of the enzymes.
abstract: The cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) gene from the alkalophilic Bacillus sp. strain no. 17-1 was cloned in Escherichia coli. The cloned CGTase gene consisted of a single open reading frame which would encode a polypeptide of 713 amino acids, and the first 27 amino acid residues comprised a signal peptide. The nucleotide sequence and the amino acid sequence of this CGTase (CGTase 17-1) gene had strong homology with those of the CGTase (CGTase 38-2) gene previously cloned in our laboratory from the alkalophilic Bacillus sp. strain no. 38-2, although the enzymic properties of the CGTase 17-1 were distinct from those of the CGTase 38-2. To analyse those enzymic properties further, we constructed 12 chimeric CGTases using three restriction nuclease sites and compared the enzymic properties of the chimeric CGTases. The N-terminal part of the enzyme was important for heat stability, and the pH-activity profile was influenced by both the N- and the C-terminal parts. A third segment was less important for enzymic properties.
authors.affiliation: Laboratory of Applied Bacteriology, Riken Institute, Saitama-ken, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kaneko
authors.forename: K B
authors.initials: KB
authors.lastname: Song
authors.forename: T
authors.initials: T
authors.lastname: Hamamoto
authors.forename: T
authors.initials: T
authors.lastname: Kudo
authors.forename: K
authors.initials: K
authors.lastname: Horikoshi
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D002678:Chimera; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data
chemical_list: D000596:Amino Acids; D004269:DNA, Bacterial; D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase