title: Vectors for regulated gene expression in the radioresistant bacterium Deinococcus radiodurans.
abstract: Deinococcus radiodurans possesses an exceptional capacity to withstand the lethal and mutagenic effects of most form of DNA damage and has received considerable interest for use in both fundamental and applied research. Here we describe vectors that allow regulated expression of Deinococcal genes for functional analysis. The vectors contain the IPTG-regulated Spac system (Pspac promoter and lacI repressor gene), originally designed for Bacillus subtilis, that we have adapted to be functional in D. radiodurans. We show that the Spac system can control the expression of a lacZ reporter gene over two orders of magnitude depending on the inducer concentration and the copy number of the lacI regulatory gene. Furthermore, we demonstrate that the Spac system can be used to regulate the synthesis of a critical repair protein, such as RecA, resulting in a conditional mitomycin-resistant cell phenotype. We have also developed tools for the construction of conditional mutants where the expression of the target gene is regulated by an inducible promoter. The utility of these conditional gene inactivation systems is exemplified by the conditional lethal phenotype of a mutant expressing gyrA from the Pspac promoter.
authors.affiliation: Institut de Génétique et Microbiologie, UMR 8621, Bât. 409, Université Paris-Sud, F-91405 Orsay, France.
authors.forename: François
authors.initials: F
authors.lastname: Lecointe
authors.forename: Geneviève
authors.initials: G
authors.lastname: Coste
authors.forename: Suzanne
authors.initials: S
authors.lastname: Sommer
authors.forename: Adriana
authors.initials: A
authors.lastname: Bailone
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D027081:DNA Gyrase / Q000235:genetics; D034301:Deinococcus / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial; D020043:Genes, Essential / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics*; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D007763:Lac Operon / Q000235:genetics; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011938:Rec A Recombinases / Q000235:genetics; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D007544:Isopropyl Thiogalactoside; D011938:Rec A Recombinases; D001616:beta-Galactosidase; D027081:DNA Gyrase