Direct regulation of Escherichia coli ribosomal protein promoters by the transcription factors ppGpp and DksA

Autor: Gina Hedberg, Patricia Sanchez-Vazquez, Justin J. Lemke, Wilma Ross, Hector L. Burgos, Richard L. Gourse
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Popis: 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.
Databáze: OpenAIRE