Single-Particle Cryo-EM Data Collection with Stage Tilt using Leginon.

Area of Science:

• Structural Biology
• Biophysics
• Microscopy

Background:

• Single-particle analysis (SPA) using cryo-electron microscopy (cryo-EM) is a key technique for determining high-resolution structures of macromolecules.
• Non-uniform particle orientation, often caused by air-water interface adherence, leads to anisotropic resolution in cryo-EM reconstructions.
• Anisotropic resolution results in uneven Fourier space sampling, limiting the quality of determined structures.

Purpose of the Study:

• To present a generalizable solution for overcoming resolution anisotropy in cryo-electron microscopy.
• To describe a tilted-stage automated data collection strategy to improve orientation distributions.
• To facilitate more isotropic Fourier space sampling for enhanced structural reconstructions.

Main Methods:

• Implementing a tilted-specimen stage strategy for automated data collection using Leginon software.
• Acquiring cryo-electron microscopy images with improved particle orientation distributions.
• Utilizing standard transmission electron microscopes (TEMs) without specialized equipment.

Main Results:

• The tilted-stage method effectively improves the uniformity of particle orientation distributions.
• This leads to more isotropic Fourier space sampling in the resulting cryo-EM maps.
• The protocol demonstrates a practical approach to mitigate anisotropic resolution in SPA.

Conclusions:

• Tilting the specimen stage is a simple yet effective method to address resolution anisotropy in cryo-electron microscopy.
• Automated data collection with Leginon and a tilted stage enhances the quality and isotropy of structural reconstructions.
• This protocol is compatible with standard TEMs and requires no additional hardware, making it widely applicable in structural biology.