Coordinated conformational and compositional dynamics drive ribosome translocation.

Area of Science:

• Molecular Biology
• Biochemistry
• Structural Biology

Background:

• The ribosome's conformational changes are crucial for protein synthesis.
• Elongation factor G (EF-G) and tRNA are key factors regulating translation elongation.

Purpose of the Study:

• To directly correlate ribosome conformation and composition during multiple rounds of elongation.
• To elucidate the role of EF-G in ribosome conformational dynamics.

Main Methods:

• Single-molecule fluorescence spectroscopy using zero-mode waveguides.
• Real-time observation of ribosome conformation and factor binding in Escherichia coli.

Main Results:

• EF-G-GTP binds preferentially to the rotated ribosome state.
• GTP hydrolysis by EF-G induces ribosome conformational changes, driving translocation.
• Simultaneous tracking of ribosome conformation and composition was achieved.

Conclusions:

• EF-G binding and GTP hydrolysis are tightly coupled to ribosome conformational transitions.
• These dynamics facilitate the release of EF-G and tRNA, ensuring accurate protein synthesis.
• Single-molecule techniques provide unprecedented insight into translation elongation mechanisms.