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Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses
Published on: February 25, 2011
Initiation factor 3-induced structural changes in the 30 S ribosomal subunit and in complexes containing tRNA(f)(Met)
T G Shapkina1, M A Dolan, P Babin
1Department of Biochemistry, North Carolina State University, Raleigh, NC, Box 7622, USA.
Journal of Molecular Biology
|June 3, 2000
Summary
Initiation factor 3 (IF3) alters 16S rRNA structure in the small ribosomal subunit, influencing tRNA selection. IF3 binding affects crosslinks within the decoding region, even without tRNA or mRNA.
Area of Science:
- Molecular Biology
- Ribosome Function
- Protein Synthesis
Background:
- Initiation factor 3 (IF3) is crucial for regulating translation initiation.
- IF3 directs the small ribosomal subunit's preference towards initiator tRNA over elongator tRNA.
Purpose of the Study:
- To investigate the structural effects of IF3 on the 30S ribosomal subunit.
- To understand how IF3 influences the interaction between the 30S subunit, mRNA, and initiator tRNA.
Main Methods:
- UV-induced RNA crosslinking was employed to map structural changes.
- Gel electrophoresis was used to analyze crosslinking patterns.
Main Results:
- IF3 binding induced alterations in three specific intramolecular crosslinks within the 16S rRNA, including in the decoding region.
- These structural changes occurred independently of tRNA(f)(Met) and mRNA.
- IF3 reduced crosslinks between 16S rRNA and both tRNA(f)(Met) and mRNA.
Conclusions:
- IF3 binding induces conformational changes in the 30S subunit's decoding region.
- IF3's interaction site is located on the 30S subunit's platform, near the decoding region.
- These findings shed light on IF3's mechanism in ensuring translation fidelity.
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