Applications of deep generative models to DNA reaction kinetics and to cryogenic electron microscopy

TL;DR

This dissertation demonstrates how deep generative models can improve understanding of DNA reaction mechanisms and cryo-EM data analysis through innovative frameworks and benchmarking.

Contribution

It introduces ViDa for DNA kinetics visualization, benchmarks deep learning methods for cryo-EM, and proposes generative models for cryo-EM map synthesis and enhancement.

Findings

ViDa effectively visualizes DNA reaction pathways.

Benchmarking reveals strengths and limitations of current deep learning methods.

Struc2mapGAN generates realistic cryo-EM density maps from structures.

Abstract

This dissertation explores how deep generative models can advance the analysis of challenging biological problems by integrating domain knowledge with deep learning. It focuses on two areas: DNA reaction kinetics and cryogenic electron microscopy (cryo-EM). In the first part, we present ViDa, a biophysics-informed framework leveraging variational autoencoders (VAEs) and geometric scattering transforms to generate biophysically-plausible embeddings of DNA reaction kinetics simulations. These embeddings are reduced to a two-dimensional space to visualize DNA hybridization and toehold-mediated strand displacement reactions. ViDa preserves structure and clusters trajectory ensembles into reaction pathways, making simulation results more interpretable and revealing new mechanistic insights. In the second part, we address key challenges in cryo-EM density map interpretation and protein structure modeling. We provide a comprehensive review and benchmarking of deep learning methods for atomic model building, with improved evaluation metrics and practical guidance. We then present Struc2mapGAN, a generative adversarial network that synthesizes high-fidelity experimental-like cryo-EM density maps from protein structures. Finally, we present CryoSAMU, a structure-aware multimodal U-Net that enhances intermediate-resolution cryo-EM maps by integrating density features with structural embeddings from protein language models via cross-attention. Overall, these contributions demonstrate the potential of deep generative models to interpret DNA reaction mechanisms and advance cryo-EM density map analysis and protein structure modeling.