title: Construction of a promoter-probe vector for Bacillus thuringiensis: the identification of cis-acting elements of the chiA locus.
abstract: The expression and application of Bacillus thuringiensis (Bt) chitinase genes have been extensively investigated. However, little information is available regarding the regulation of chitinase gene expression in Bt. In this study, a shuttle promoter-probe vector was constructed incorporating the thermostable β-galactosidase gene bgaB of B. stearothermophilus as the reporter for the study of Bt promoters. Using this plasmid, the activity of the chiA gene promoter in Bt was investigated. Deletion analysis of the putative chiA promoter region revealed that the sequence located ~75 bp DNA from positions -116 to -42, with respect to the translation start site, is the core promoter of chiA gene. Furthermore, a site for chitin induction was identified near position -36. This site for negative regulation was indicated downstream of the RNA polymerase binding sites of the promoter of chiA. The expression of chiA started in cell grown for about 6 h and reached the maximum after 60 h of incubation. Induction of chiA expression by chitin was demonstrated by an increase in β-galactosidase activity of ~2.5-fold.
authors.affiliation: Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, People's Republic of China.
authors.forename: Chi-Chu
authors.initials: CC
authors.lastname: Xie
authors.forename: Yang
authors.initials: Y
authors.lastname: Luo
authors.forename: Yue-Hua
authors.initials: YH
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Cai
mesh_terms: D001413:Bacillus thuringiensis / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002688:Chitinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid
chemical_list: D001426:Bacterial Proteins; D002688:Chitinases