Biophysical Society Thematic Meeting | Trieste 2024

Emerging Theoretical Approaches to Complement Single-Particle Cryo-EM Wednesday Speaker Abstracts

CRYOPROS: ADDRESSING PREFERRED ORIENTATION IN SINGLE-PARTICLE CRYO-EM THROUGH AI-GENERATED AUXILIARY PARTICLES Mingxu Hu 1,2 ; Hui Zhang 2 ; Dihan Zheng 2 ; Chenglong Bao 2 ; 1 Shenzhen Medical Academy of Research and Translation, Beijing, China 2 Tsinghua University, Beijing, China Preferred orientation presents a persistent challenge in cryo-EM single particle analysis. Despite extensive experimental study, computational analysis of preferred orientation artifacts from real world datasets remains an important yet underexplored perspective. In this study, after analyzing datasets exhibiting preferred orientation, we identified misalignment as the primary challenge. This led us to develop cryoPROS, a computational framework designed to address this issue by co-refining synthesized and experimental data. Utilizing a self-supervised deep generative model, cryoPROS synthesizes auxiliary particles to effectively eliminate misalignment errors in experimental particles through a co-refinement process, achieving near-atomic resolution with the untilted HA-trimer dataset. With extensions, cryoPROS resolved high-resolution structures of two membrane proteins, P001-Y and Na X , affected by preferred orientation and micelle effects, and uncovered a new state of hormone-sensitive lipase dimer within a dataset afflicted by both preferred orientation and heterogeneity. Extensive experiments validated the robustness of cryoPROS and its negligible risk of model bias.

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