TYGRESS

TYGRESS integrates cryo-electron tomography (cryo-ET) and single-particle cryo-electron microscopy (SP-cryo-EM) to perform in situ 3D reconstruction of subcellular macromolecular assemblies at nanometer resolution.

Key Features:

• Hybrid integration: Integrates SP-cryo-EM images with cryo-ET-derived subtomogram averaging to combine high contrast with 3D spatial context.
• Subtomogram averaging: Uses subtomogram averaging for 3D alignment and averaging of particles within crowded cellular environments.
• Improved signal-to-noise and contrast: Leverages the superior signal-to-noise ratio and contrast of SP-cryo-EM images to enhance reconstruction quality.
• Radiation-damage considerations: Utilizes SP-cryo-EM imaging properties associated with minimal radiation damage to obtain high-quality input images.
• Nanometer resolution: Enables reconstructions approaching nanometer resolution, demonstrated on an intact ciliary axoneme resolved to ~12 Å.
• In situ context: Retains native cellular context for macromolecular complexes during 3D reconstruction.
• Applicability: Applicable to cellular complexes amenable to subtomogram averaging.

Scientific Applications:

• Ciliary axoneme structure determination: Determination of the intact ciliary axoneme at up to ~12 Å resolution.
• In situ structural biology: High-resolution 3D reconstruction of complex subcellular assemblies within their native cellular environments.
• Study of subtomogram-amenable complexes: Structural analysis of cellular complexes suitable for subtomogram averaging to reveal architecture not resolvable by cryo-ET alone.

Methodology:

Computationally integrates SP-cryo-EM image data with cryo-ET subtomogram averaging and 3D alignment to reconstruct macromolecular assemblies within cells.