CryoUNI Latent Density Encodes Boltzmann Conformational Energy Landscapes
Supporting evidence
- CryoUNI Latent PCs Match Integrin Leg Angles from MD
- WAVE Detects Density-Peak States Without Predefined State Number
By grounding cryo-EM latent spaces in physical probability distributions and validating them against molecular dynamics, this work overturns the discrete-class paradigm and makes rare conformational intermediates and continuous transition pathways directly accessible from experimental data.
Cryo-EM particle images encode a physically grounded conformational landscape where latent density quantitatively reflects the probabilistic distribution of molecular states according to Boltzmann statistics, enabling automated discovery of low-population intermediate states invisible to conventional methods, direct experimental resolution of continuous conformational pathways, and energy-guided particle selection that improves reconstruction quality.
A protein populates a landscape of structural states, abundant snapshots of which are sampled in every cryo-EM experiment. Current analysis averages these snapshots into single density maps or partitions them into discrete classes, discarding the continuous dynamics encoded in the data. Continuous latent-space methods offer a promising alternative, yet whether their learned representations are physically grounded remains unresolved. Here, we realize cryo-EM as structural landscape microscopy, in which latent density directly reflects the probabilistic distribution of molecular states. A central question is whether such a landscape reflects physical reality. For integrin αvβ8, the learned landscape shows strong agreement with independently derived molecular dynamics simulations, supporting its physical plausibility. We then apply the landscape to structural states that conventional cryo-EM cannot resolve. For LIS1-mediated dynein activation, the landscape reveals a spectrum of states from dominant conformations to low-population intermediates defined by distinct binding modes, including a previously unresolved state. For the KCTD5/CUL3NTD/Gβγ complex, the landscape resolves continuous conformational pathways directly from experimental data. Probability-guided particle selection further improves reconstruction quality.