Focused classification and refinement in high-resolution cryo-EM structural analysis of ribosome complexes

Area of Science:

• Structural Biology
• Biochemistry
• Microscopy

Background:

• Cryo-electron microscopy (cryo-EM) has been pivotal in analyzing protein synthesis in prokaryotic and eukaryotic ribosomes.
• Ribosome studies have driven methodological advancements in single-particle cryo-EM, including automated data collection and image processing.

Purpose of the Study:

• To review recent ribosome structures obtained via cryo-EM.
• To highlight how cryo-EM advances enable detailed analysis of molecular interactions and modifications.

Main Methods:

• Single particle cryo-electron microscopy (cryo-EM).
• Advanced particle sorting techniques for heterogeneity.
• 3D structure sorting with focused classification and refinement.

Main Results:

• Achieved local resolution levels better than 3Å for ribosome structures.
• Enabled visualization of drug interactions with RNA and protein side-chains.
• Allowed visualization of chemical modifications on ribosomal RNA.

Conclusions:

• Cryo-EM provides unprecedented insights into ribosome structure and function.
• High-resolution cryo-EM is crucial for understanding drug-ribosome interactions.
• Cryo-EM has broad potential for structure-based drug design beyond ribosomes.