title: Interactions of the antizyme AtoC with regulatory elements of the Escherichia coli atoDAEB operon.
abstract: AtoC has a dual function as both an antizyme, the posttranslational inhibitor of polyamine biosynthetic enzymes, and the transcriptional regulator of genes involved in short-chain fatty acid catabolism (the atoDAEB operon). We have previously shown that AtoC is the response regulator of the AtoS-AtoC two-component signal transduction system that activates atoDAEB when Escherichia coli is exposed to acetoacetate. Here, we show that the same cis elements control both promoter inducibility and AtoC binding. Chromatin immunoprecipitation experiments confirmed the acetoacetate-inducible binding of AtoC to the predicted DNA region in vivo. DNase I protection footprinting analysis revealed that AtoC binds two 20-bp stretches, constituting an inverted palindrome, that are located at -146 to -107 relative to the transcription initiation site. Analyses of promoter mutants obtained by in vitro chemical mutagenesis of the atoDAEB promoter verified both the importance of AtoC binding for the inducibility of the promoter by acetoacetate and the sigma54 dependence of atoDAEB expression. The integration host factor was also identified as a critical component of the AtoC-mediated induction of atoDAEB.
authors.affiliation: Department of Pharmaceutical Sciences, Laboratory of Biochemistry, Aristotle University, Thessaloniki 54124, Greece.
authors.forename: Meropi K
authors.initials: MK
authors.lastname: Matta
authors.forename: Efthimia E
authors.initials: EE
authors.lastname: Lioliou
authors.forename: Cynthia H
authors.initials: CH
authors.lastname: Panagiotidis
authors.forename: Dimitrios A
authors.initials: DA
authors.lastname: Kyriakidis
authors.forename: Christos A
authors.initials: CA
authors.lastname: Panagiotidis
mesh_terms: D000090:Acetoacetates / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D018983:DNA Footprinting; D004252:DNA Mutational Analysis; D004269:DNA, Bacterial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics; D016296:Mutagenesis; D009154:Mutation; D009876:Operon; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D050436:Regulatory Elements, Transcriptional
chemical_list: D000090:Acetoacetates; C505587:AtoC protein, E coli; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D005232:Fatty Acids, Volatile; C016635:acetoacetic acid