Related Experiment Video
Updated: May 4, 2026
08:07
Single Molecule Fluorescence Energy Transfer Study of Ribosome Protein Synthesis
Published on: July 6, 2021
2.2K
Structured mRNA induces the ribosome into a hyper-rotated state
Peiwu Qin1, Dongmei Yu, Xiaobing Zuo
1Department of Biochemistry, University of Missouri, Columbia, MO, USA.
EMBO Reports
|January 10, 2014
Summary
The ribosome unwinds mRNA structures during translocation, revealing a new hyper-rotated state. This finding offers structural insights into the ribosome's helicase activity and reading frame maintenance.
Area of Science:
- Molecular Biology
- Structural Biology
- Biophysics
Background:
- Protein synthesis involves ribosome translocation of mRNA and tRNA.
- mRNA secondary structures can impede translocation, requiring unwinding.
- The ribosome's intrinsic RNA unwinding mechanism is not fully understood.
Purpose of the Study:
- To elucidate the structural mechanism of ribosome-mediated RNA unwinding.
- To investigate the ribosome's conformational changes during translocation of structured mRNA.
- To understand the role of these changes in reading frame maintenance.
Main Methods:
- Single molecule Förster resonance energy transfer (smFRET).
- Small angle X-ray scattering (SAXS).
- Utilized the frameshift-inducing dnaX hairpin as a model RNA structure.
Main Results:
- Identified a novel global conformational state of the ribosome.
- Observed ribosome subunit hyper-rotation and L1 stalk opening in the presence of the dnaX hairpin.
- Demonstrated ribosome-induced unwinding of structured mRNA.
Conclusions:
- The ribosome adopts a hyper-rotated, L1 stalk-open state to facilitate RNA unwinding.
- This conformational state provides structural basis for the ribosome's helicase activity.
- Findings have implications for understanding mRNA translocation and reading frame maintenance.
Related Concept Videos
02:33Initiation of Translation
24.7K
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
24.7K
02:33Initiation of Translation
7.0K
7.0K
02:53Ribosomal RNA Synthesis
12.3K
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
12.3K
02:53Ribosomal RNA Synthesis
3.7K
3.7K
01:29Translational Regulation
877
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
877
01:34Directing Proteins to the Rough Endoplasmic Reticulum
12.0K
The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
12.0K