Related Experiment Videos
The tRNA-tufB operon transcription termination and processing upstream from tufB
J H Van Delft1, D S Schmidt, L Bosch
1Department of Biochemistry, University of Leiden, The Netherlands.
Journal of Molecular Biology
|October 20, 1987
Summary
Escherichia coli tufB gene transcription is regulated by a termination site after upstream tRNA genes. Eliminating this site uncouples tRNA and tufB RNA synthesis, increasing EF-TuB production.
Area of Science:
- Molecular Biology
- Genetics
- Microbiology
Background:
- The Escherichia coli tufA and tufB genes encode the polypeptide chain elongation factor EF-Tu.
- The tufB gene is part of a cotranscript with four upstream tRNA genes (thrU, tyrU, glyT, thrT).
Purpose of the Study:
- To investigate the in vivo processing of the tufB transcript.
- To identify regulatory elements controlling tufB transcription within the tRNA-tufB operon.
Main Methods:
- S1 nuclease fine mapping to determine transcript processing sites.
- Plasmid-based genetic manipulation involving deletions within the tRNA-tufB operon.
- Quantification of transcription rates and RNA levels.
Main Results:
- In vivo processing generates a 1320 nucleotide tufB transcript.
- A specific processing site is located upstream of the tufB initiation codon.
- Deletion of upstream tRNA genes and intergenic regions significantly increases tufB transcription and RNA levels.
- Plasmid-borne EF-TuB levels also increase following the deletion.
Conclusions:
- A transcription termination site likely exists after the thrT gene, regulating the tRNA-tufB operon.
- This termination site uncouples tRNA synthesis from tufB transcription.
- Regulation of this termination site impacts EF-Tu production.