Homeostatic regulation of supercoiling sensitivity coordinates transcription of the bacterial genome.
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.
Blot
Nicolas
N
International University Bremen, Campus Ring 1, 28759 Bremen, Germany.
Mavathur
Ramesh
R
Geertz
Marcel
M
Travers
Andrew
A
Muskhelishvili
Georgi
G
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
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