title: Homeostatic regulation of supercoiling sensitivity coordinates transcription of the bacterial genome.
abstract: Regulation of cellular growth implies spatiotemporally coordinated programmes of gene transcription. A central question, therefore, is how global transcription is coordinated in the genome. The growth of the unicellular organism Escherichia coli is associated with changes in both the global superhelicity modulated by cellular topoisomerase activity and the relative proportions of the abundant DNA-architectural chromatin proteins. Using a DNA-microarray-based approach that combines mutations in the genes of two important chromatin proteins with induced changes of DNA superhelicity, we demonstrate that genomic transcription is tightly associated with the spatial distribution of supercoiling sensitivity, which in turn depends on chromatin proteins. We further demonstrate that essential metabolic pathways involved in the maintenance of growth respond distinctly to changes of superhelicity. We infer that a homeostatic mechanism organizing the supercoiling sensitivity is coordinating the growth-phase-dependent transcription of the genome.
authors.affiliation: International University Bremen, Campus Ring 1, 28759 Bremen, Germany.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Blot
authors.forename: Ramesh
authors.initials: R
authors.lastname: Mavathur
authors.forename: Marcel
authors.initials: M
authors.lastname: Geertz
authors.forename: Andrew
authors.initials: A
authors.lastname: Travers
authors.forename: Georgi
authors.initials: G
authors.lastname: Muskhelishvili
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002843:Chromatin / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D004278:DNA, Superhelical / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D035021:Factor For Inversion Stimulation Protein; D016680:Genome, Bacterial; D006706:Homeostasis; D008954:Models, Biological; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D002843:Chromatin; D004269:DNA, Bacterial; D004278:DNA, Superhelical; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D035021:Factor For Inversion Stimulation Protein; C501034:Fis protein, E coli; C031908:H-NS protein, bacteria; D014157:Transcription Factors