title: Direct regulation of Escherichia coli ribosomal protein promoters by the transcription factors ppGpp and DksA.
abstract: We show here that the promoters for many of the Escherichia coli ribosomal protein operons are regulated directly by two transcription factors, the small RNA polymerase-binding protein DksA and the nutritional stress-induced nucleotide ppGpp. ppGpp and DksA work together to inhibit transcription initiation from ribosomal protein promoters in vitro and in vivo. The degree of promoter regulation by ppGpp/DksA varies among the r-protein promoters, but some are inhibited almost as much as rRNA promoters. Thus, many r-protein operons are regulated at the level of transcription in addition to their control by the classic translational feedback systems discovered ~30 y ago. We conclude that direct control of r-protein promoters and rRNA promoters by the same signal, ppGpp/DksA, makes a major contribution to the balanced and coordinated synthesis rates of all of the ribosomal components.
authors.affiliation: Department of Bacteriology, University of Wisconsin, Madison, WI 53719, USA.
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Lemke
authors.forename: Patricia
authors.initials: P
authors.lastname: Sanchez-Vazquez
authors.forename: Hector L
authors.initials: HL
authors.lastname: Burgos
authors.forename: Gina
authors.initials: G
authors.lastname: Hedberg
authors.forename: Wilma
authors.initials: W
authors.lastname: Ross
authors.forename: Richard L
authors.initials: RL
authors.lastname: Gourse
mesh_terms: D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011755:Pyrophosphatases / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*; D001616:beta-Galactosidase
chemical_list: D029968:Escherichia coli Proteins; D012269:Ribosomal Proteins; D014157:Transcription Factors; C090751:dksA protein, E coli; C027627:guanosine-3',5'-bis(diphosphate) 3'-pyrophosphatase; D001616:beta-Galactosidase; D011755:Pyrophosphatases