Redundancy of primary RNA-binding functions of the bacterial transcription terminator Rho.
Bottom Line: The bacterial transcription terminator, Rho, terminates transcription at half of the operons.These terminators function optimally only through a NusG-assisted recruitment and activation of Rho.Our data also indicate that at these terminators, Rho-EC-bound NusG interaction facilitates the isomerization of Rho into a translocase-competent form by stabilizing the interactions of mRNA with the secondary RNA binding site, thereby overcoming the defects of the primary RNA binding functions.
Affiliation: Laboratory of Transcription, Center for DNA Fingerprinting and Diagnostics, Tuljaguda Complex, 4-1-714 Mozamjahi Road, Nampally, Hyderabad 500001, India.Show MeSH
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Mentions: For these assays, we have used MC4100 strains that have lost rac prophage (rac−) during the propagation, and deletion of this prophage allowed the strain to survive in the presence of all the rho and nusG mutants. This MC4100 also has the trac terminator cassette inserted into the genome as a λRS45 lysogen (RS1428). nusG mutations were then inserted into the genome of RS1428 by linear DNA transformations to produce RS1514 (G146D) and RS1523 (L158Q). These two resultant strains were transformed with WT and different Rho mutants (Y80C and N340S) cloned in a low copy number plasmid, pCL1920 (pHYD567), and subsequently the chromosomal rho was removed by transducing a rho::kanR cassette via P1 transduction. Two transductants of each mutants were re-streaked to measure the synthetic lethality (Figure 3F).
Affiliation: Laboratory of Transcription, Center for DNA Fingerprinting and Diagnostics, Tuljaguda Complex, 4-1-714 Mozamjahi Road, Nampally, Hyderabad 500001, India.