| Literature DB >> 3156375 |
R L Gourse, Y Takebe, R A Sharrock, M Nomura.
Abstract
We have constructed a conditional rRNA gene expression system by fusing a plasmid-encoded rrnB operon to the lambda PL promoter/operator. It was thereby possible to study the events that lead to the regulation of chromosomal rRNA and tRNA synthesis after overproduction of rRNA. rRNA induction resulted in a 2-fold increase in 30S and 50S free ribosomal subunits, whereas the polysome fraction was unaffected. Overproduction of rRNA and "free" ribosomes produced a large repression of rRNA and tRNA synthesis from chromosomal genes and a smaller increase in the concentration of guanosine tetraphosphate. These results lend support to the ribosome feedback regulation model: rRNA and tRNA operons are negatively regulated, either directly or through some intermediate, by free, nontranslating ribosomes.Entities:
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Year: 1985 PMID: 3156375 PMCID: PMC397195 DOI: 10.1073/pnas.82.4.1069
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN: 0027-8424 Impact factor: 11.205