title: Doc-mediated cell killing in Shigella flexneri using a C1/LacI controlled expression system.
abstract: In this report we describe the development of a highly stringent and dually regulated promoter system for Shigella flexneri. Dual regulation was provided by utilizing a promoter susceptible to control by the bacteriophage P1 temperature-sensitive C1 repressor that in turn was under the transcriptional control of LacI. The level of induction/repression ratios observed was up to 3700-fold in S. flexneri. The general utility of this promoter system was evaluated by demonstrating that the bacteriophage P1 post-segregational killer protein Doc mediates a bactericidal effect in S. flexneri. This represents the first report of Doc (death on curing)-mediated killing in this Gram-negative species.
authors.affiliation: Department of Microbiology and Immunology, BSB 201, Medical University of South Carolina, 173 Ashley Avenue, Charleston 29403, USA. schofida@musc.edu
authors.forename: David A
authors.initials: DA
authors.lastname: Schofield
authors.forename: Caroline
authors.initials: C
authors.lastname: Westwater
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Dolan
authors.forename: James S
authors.initials: JS
authors.lastname: Norris
authors.forename: Michael G
authors.initials: MG
authors.lastname: Schmidt
mesh_terms: D001426:Bacterial Proteins; D017101:Bacteriophage P1 / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005822:Genetic Vectors; D056968:Lac Repressors; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012763:Shigella flexneri / Q000235:genetics / Q000254:growth & development*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C083664:Doc protein, Enterobacteria phage P1; D029968:Escherichia coli Proteins; D056968:Lac Repressors; D012097:Repressor Proteins; D014764:Viral Proteins; C076896:repressor protein C1, bacteriophage