Related Experiment Video
Updated: Aug 11, 2026

Inducing a Site Specific Replication Blockage in E. coli Using a Fluorescent Repressor Operator System
Published on: August 21, 2016
Relaxation of stable RNA synthesis by a plasmid-borne locus
Abstract:
The plasmid pMY3, which was constructed so as to express the Su+7 amber suppressor tRNA gene, also relaxes control of stable RNA synthesis in stringent cells. The relaxation is not growth medium or strain-dependent and does not occur in the presence of the vehicle alone. When expression of the effective sequence is diminished, in a lysogen of phi 80d3 ilv+Su+7, the sequence no longer affects RNA synthesis. The relaxation is general, extending to all or almost all tRNA loci, including tRNAs located in the ribosomal spacer regions, and to all ribosomal RNAs. Relaxed plasmid-carrying strains are still able to elevate guanosine tetra- and penta-phosphate levels in response to amino acid starvation, but steady state levels are somewhat diminished. Aminoacyl-tRNA falls to control levels when the plasmid-carrying strain is deprived of amino acid. Therefore, the relaxed strain perceives amino acid starvation, but does not respond normally. These properties define a novel locus which relaxes stringent control.
More Related Videos
Related Concept Videos
Types of RNA
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Types of RNA
RNA Performs Diverse...
Coordination of Gene Expression Processes in Bacteria
Translational Regulation
Stringent Response in E. coli

