title: Conserved promoter motif is required for cell cycle timing of dnaX transcription in Caulobacter.
abstract: Cells use highly regulated transcriptional networks to control temporally regulated events. In the bacterium Caulobacter crescentus, many cellular processes are temporally regulated with respect to the cell cycle, and the genes required for these processes are expressed immediately before the products are needed. Genes encoding factors required for DNA replication, including dnaX, dnaA, dnaN, gyrB, and dnaK, are induced at the G(1)/S-phase transition. By analyzing mutations in the dnaX promoter, we identified a motif between the -10 and -35 regions that is required for proper timing of gene expression. This motif, named RRF (for repression of replication factors), is conserved in the promoters of other coordinately induced replication factors. Because mutations in the RRF motif result in constitutive gene expression throughout the cell cycle, this sequence is likely to be the binding site for a cell cycle-regulated transcriptional repressor. Consistent with this hypothesis, Caulobacter extracts contain an activity that binds specifically to the RRF in vitro.
authors.affiliation: Department of Developmental Biology, Stanford University, Stanford, California 94305, USA.
authors.forename: K C
authors.initials: KC
authors.lastname: Keiler
authors.forename: L
authors.initials: L
authors.lastname: Shapiro
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D016935:Caulobacter crescentus / Q000166:cytology / Q000235:genetics*; D002453:Cell Cycle / Q000235:genetics; D017124:Conserved Sequence; D027081:DNA Gyrase; D004258:DNA Polymerase III / Q000235:genetics* / Q000378:metabolism; D004261:DNA Replication; D004250:DNA Topoisomerases, Type II / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase; D029968:Escherichia coli Proteins; D016193:G1 Phase; D015964:Gene Expression Regulation, Bacterial; D014644:Genetic Variation; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D016196:S Phase; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; C103076:DnaX protein, Bacteria; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase; C083980:dnaN protein, Bacteria; C063842:dnaK protein, E coli; D027081:DNA Gyrase; D004250:DNA Topoisomerases, Type II