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Published on: June 24, 2019
Distinct uS11/Rps14 interactions with the translation preinitiation complex differentially alter the accuracy of
Nidhi Gupta1, Indira Bag2, Jyothsna Visweswaraiah3,4
1Regional Centre for Biotechnology, 3rd milestone Gurgaon-Faridabad Expressway, Faridabad 121001, India.
Nucleic Acids Research
|March 29, 2025
Summary
The study reveals how the ribosomal protein uS11/Rps14 controls translation initiation accuracy. Specific interactions with ribosomal RNA stabilize distinct pre-initiation complex (PIC) states, ensuring correct start codon recognition.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Eukaryotic translation initiation involves the 43S pre-initiation complex (PIC) scanning mRNA for a start codon.
- PIC conformation shifts from an open scanning state to a closed arrested state upon start codon recognition.
- The role of ribosomal protein uS11/Rps14 in this conformational change and its impact on initiation accuracy was unclear.
Purpose of the Study:
- To investigate the function of uS11/Rps14 in regulating PIC conformation during translation initiation.
- To determine how uS11/Rps14 interactions with ribosomal RNA influence start codon recognition accuracy.
Main Methods:
- Utilized cryo-electron microscopy (cryo-EM) reconstructions of yeast PICs.
- Employed site-directed mutagenesis of uS11/Rps14 to disrupt specific rRNA interactions.
- Performed in vitro reconstitution assays with mutated PICs and initiation complexes.
Main Results:
- Mutations disrupting uS11/Rps14's interaction with rRNA in the open PIC state led to increased initiation at non-optimal sites.
- Mutations affecting uS11/Rps14's interaction with rRNA in the closed PIC state resulted in enhanced initiation accuracy.
- Specific mutations stabilized the ternary complex (TC) binding or accelerated its dissociation, correlating with initiation fidelity.
Conclusions:
- Distinct interactions between uS11/Rps14 and rRNA are crucial for stabilizing the open and closed PIC conformations.
- These interactions precisely regulate the accuracy of translation start codon selection in vivo.
- uS11/Rps14 acts as a key mediator of conformational dynamics that govern translation initiation fidelity.
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