title: Isolation and molecular characterization of a stationary phase promoter useful for gene expression in Gordonia.
abstract: Gordonia are gram-positive bacteria belonging to Actinomycetes family with a wide variety of industrial and environmental applications. The genetic toolbox, however, is limited for manipulation of these organisms. In the present study, a new promoter has been isolated from Gordonia sp. IITR 100 and characterized in detail. The promoter was found to be functional in Escherichia coli. The minimal promoter was identified in a 166bp fragment by deletion mapping. The putative -35 and -10 hexamer showed four and five nucleotide matches respectively with the E. coli consensus sequence. Three direct repeats and an imperfect inverted repeat upstream to -35 were found. The isolated promoter was found to be six times stronger than the Pkan promoter observed by cloning lacZ downstream to each of them in a plasmid in E. coli. The β-galactosidase activity was maximum at stationary phase and found to be ~800MU for Gordonia sp. IITR 100 and E. coli. This is the first report of a stationary phase promoter isolated and characterized from Gordonia.
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, India.
authors.forename: Pooja
authors.initials: P
authors.lastname: Singh
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, India.
authors.forename: Sahil
authors.initials: S
authors.lastname: Chachan
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, India.
authors.forename: Divya
authors.initials: D
authors.lastname: Singhi
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, India. Electronic address: preetisrivastava@hotmail.com.
authors.forename: Preeti
authors.initials: P
authors.lastname: Srivastava
mesh_terms: D020029:Base Pairing / Q000235:genetics; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D015964:Gene Expression Regulation, Bacterial; D033601:Gordonia Bacterium / Q000235:genetics*; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion; D001616:beta-Galactosidase / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D001616:beta-Galactosidase
keywords: Deletion mapping; E. coli; Gordonia; Promoter; Stationary phase