PMID:12419222

Citation	Wendrich, TM, Blaha, G, Wilson, DN, Marahiel, MA and Nierhaus, KH (2002) Dissection of the mechanism for the stringent factor RelA. Mol. Cell 10:779-88
Abstract	During conditions of nutrient deprivation, ribosomes are blocked by uncharged tRNA at the A site. The stringent factor RelA binds to blocked ribosomes and catalyzes synthesis of (p)ppGpp, a secondary messenger that induces the stringent response. We demonstrate that binding of RelA and (p)ppGpp synthesis are inversely coupled, i.e., (p)ppGpp synthesis decreases the affinity of RelA for the ribosome. RelA binding to ribosomes is governed primarily by mRNA, but independently of ribosomal protein L11, while (p)ppGpp synthesis strictly requires uncharged tRNA at the A site and the presence of L11. A model is proposed whereby RelA hops between blocked ribosomes, providing an explanation for how low intracellular concentrations of RelA (1/200 ribosomes) can synthesize (p)ppGpp at levels that accurately reflect the starved ribosome population.
Links	PubMed
Keywords	Adenosine Triphosphate/pharmacology; Binding Sites; Escherichia coli/metabolism; Gene Expression Regulation, Bacterial; Guanosine Tetraphosphate/biosynthesis; Guanosine Triphosphate/pharmacology; Ligases/metabolism; Protein Binding/drug effects; Protein Biosynthesis; RNA, Bacterial/metabolism; RNA, Messenger/metabolism; RNA, Transfer/metabolism; Ribosomal Proteins/metabolism; Ribosomes/metabolism; Tetracycline/pharmacology
edit table

Significance

You can help EcoliWiki by summarizing why this paper is useful

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Add links to pages that link here (e.g. gene, product, method pages)

See Help:References for how to manage references in EcoliWiki.