Modular Assembly of the Bacterial Large Ribosomal Subunit

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Ribosome biogenesis is crucial for protein synthesis but difficult to study in vivo due to transient intermediates.
• Understanding the dynamic assembly of ribosomes is key to deciphering cellular machinery.

Purpose of the Study:

• To visualize and characterize ribosome assembly intermediates in vivo.
• To elucidate the pathway and dynamics of ribosome biogenesis.

Main Methods:

• A genetic system was employed to induce the accumulation of ribosome assembly intermediates.
• Quantitative mass spectrometry and single-particle cryo-electron microscopy (cryo-EM) were used for high-resolution structural analysis.

Main Results:

• Thirteen distinct ribosome assembly intermediates were identified and resolved to ~4-5 Å resolution.
• Ribosome biogenesis was shown to be a parallel and cooperative process involving structured rRNA and proteins.
• The assembly pathway was found to be dynamic and adaptable, allowing for re-routing.

Conclusions:

• This study provides unprecedented insight into the in vivo landscape of ribosome assembly.
• The developed methods offer tools for characterizing additional assembly pathways for ribosomes and other macromolecular machines.