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Updated: Mar 8, 2026
10:37
Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs
Published on: May 10, 2018
13.2K
Dynamics of IRES-mediated translation
Alex G Johnson1,2, Rosslyn Grosely2, Alexey N Petrov2
1Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA.
Summary
Viral internal ribosome entry sites (IRESs) use RNA structures to initiate protein synthesis, bypassing canonical pathways. Cryo-EM and single-molecule studies reveal IRES-ribosome complex structures and dynamics.
Area of Science:
- Molecular Biology
- Virology
- Structural Biology
Background:
- Viral internal ribosome entry sites (IRESs) are RNA elements that recruit ribosomes for protein synthesis.
- IRESs simplify eukaryotic translation initiation, often using fewer initiation factors.
- Cricket paralysis virus (CrPV) and hepatitis C virus (HCV) IRESs are simple models that bind directly to the 40S ribosomal subunit.
Purpose of the Study:
- To review recent advances in understanding HCV- and CrPV-type IRESs.
- To highlight structural and dynamic insights gained from studying these IRESs.
- To emphasize the synergy between cryo-electron microscopy (cryo-EM) and single-molecule studies.
Main Methods:
- Cryogenic electron microscopy (cryo-EM) for high-resolution structural models.
- Single-molecule analysis for studying dynamics.
- Biochemical research to clarify mechanisms.
Main Results:
- High-resolution structural models of ribosome:IRES complexes have been generated.
- Dynamics studies have elucidated the conformational changes during initiation.
- These studies have clarified decades of biochemical research on translation initiation.
Conclusions:
- HCV- and CrPV-type IRESs are valuable models for ribosome initiation studies.
- Cryo-EM and single-molecule techniques provide powerful insights into IRES function.
- Understanding IRES mechanisms advances knowledge of translation regulation and viral replication.
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