Eukaryotic rpL10 drives ribosomal rotation.

Area of Science:

• Molecular Biology
• Biochemistry
• Genetics

Background:

• Ribosomes exist in non-rotated and rotated states during the elongation cycle.
• Ribosomal proteins play critical roles in regulating ribosome function and conformational dynamics.

Purpose of the Study:

• To investigate the role of an internal loop in yeast ribosomal protein rpL10 as a controller of ribosome conformational states.
• To elucidate the allosteric mechanisms linking rpL10 to intersubunit rotation and ribosome function.

Main Methods:

• Site-directed mutagenesis of the rpL10 internal loop.
• Chemical modification analysis of ribosomal RNA (rRNA).
• Biochemical assays measuring catalytic activity and translational fidelity.

Main Results:

• Mutations in the rpL10 loop altered the equilibrium between non-rotated and rotated states.
• These mutations led to allosteric defects, impacting catalytic, biochemical, and translational fidelity.
• A mutation in rpL3 suppressed the rpL10 mutant, restoring rotational equilibrium and function.

Conclusions:

• The internal loop of rpL10 is a central controller of ribosome rotation.
• rpL10 regulates intersubunit rotation through allosteric interactions, affecting ribosome-wide function.
• Ribosome rotational status is critical for late-stage maturation of the large ribosomal subunit (LSU).