Growth rate regulation inEscherichia coli
Open Access
- 1 March 2012
- journal article
- review article
- Published by Oxford University Press (OUP) in FEMS Microbiology Reviews
- Vol. 36 (2), 269-287
- https://doi.org/10.1111/j.1574-6976.2011.00279.x
Abstract
Growth rate regulation in bacteria has been an important issue in bacterial physiology for the past 50 years. This review, using Escherichia coli as a paradigm, summarizes the mechanisms for the regulation of rRNA synthesis in the context of systems biology, particularly, in the context of genome-wide competition for limited RNA polymerase (RNAP) in the cell under different growth conditions including nutrient starvation. The specific location of the seven rrn operons in the chromosome and the unique properties of the rrn promoters contribute to growth rate regulation. The length of the rrn transcripts, coupled with gene dosage effects, influence the distribution of RNAP on the chromosome in response to growth rate. Regulation of rRNA synthesis depends on multiple factors that affect the structure of the nucleoid and the allocation of RNAP for global gene expression. The magic spot ppGpp, which acts with DksA synergistically, is a key effector in both the growth rate regulation and the stringent response induced by nutrient starvation, mainly because the ppGpp level changes in response to environmental cues. It regulates rRNA synthesis via a cascade of events including both transcription initiation and elongation, and can be explained by an RNAP redistribution (allocation) model.Keywords
This publication has 164 references indexed in Scilit:
- The Transcription Factor DksA Prevents Conflicts between DNA Replication and Transcription MachineryCell, 2010
- Super DksAs: substitutions in DksA enhancing its effects on transcription initiationThe EMBO Journal, 2009
- Still Looking for the Magic Spot: The Crystallographically Defined Binding Site for ppGpp on RNA Polymerase Is Unlikely to Be Responsible for rRNA Transcription RegulationJournal of Molecular Biology, 2008
- Mechanism of regulation of transcription initiation by ppGpp. II. Models for positive control based on properties of RNAP mutants and competition for RNAPJournal of Molecular Biology, 2001
- Mechanism of regulation of transcription initiation by ppGpp. I. Effects of ppGpp on transcription initiation in vivo and in vitroJournal of Molecular Biology, 2001
- The bacterial DNA-binding protein H-NS represses ribosomal RNA transcription by trapping RNA polymerase in the initiation complexJournal of Molecular Biology, 2000
- Characterization of the cytoplasm of Escherichia coli K-12 as a function of external osmolarityJournal of Molecular Biology, 1991
- Alteration of the growth-rate-dependent regulation of Escherichia coli tyrT expression by promoter mutationsJournal of Molecular Biology, 1986
- Stringent response in Escherichia coli induces expression of heat shock proteinsJournal of Molecular Biology, 1985
- Rate-limiting steps in RNA chain initiation.Proceedings of the National Academy of Sciences, 1980