Proteins play a critical role in carrying out biological functions, and their 3D structures are essential in determining their functions. Accurately predicting the conformation of protein side-chains given their backbones is important for applications in protein structure prediction, design and protein-protein interactions. Traditional methods are computationally intensive and have limited accuracy, while existing machine learning methods treat the problem as a regression task and overlook the restrictions imposed by the constant covalent bond lengths and angles. In this work, we present DiffPack, a torsional diffusion model that learns the joint distribution of side-chain torsional angles, the only degrees of freedom in side-chain packing, by diffusing and denoising on the torsional space. To avoid issues arising from simultaneous perturbation of all four torsional angles, we propose autoregressively generating the four torsional angles from $\chi_1$ to $\chi_4$ and training diffusion models for each torsional angle. We evaluate the method on several benchmarks for protein side-chain packing and show that our method achieves improvements of 11.9% and 13.5% in angle accuracy on CASP13 and CASP14, respectively, with a significantly smaller model size ($60\times$ fewer parameters). Additionally, we show the effectiveness of our method in enhancing side-chain predictions in the AlphaFold2 model.

Feature selection is a fundamental step in model development, shaping both predictive performance and interpretability. Y et, most widely used methods focus on predictive accuracy, and their performance degrades in the presence of correlated predictors. To address this gap, we introduce TangledFeatures, a framework for feature selection in correlated feature spaces. It identifies representative features from groups of entangled predictors, reducing redundancy while retaining explanatory power. The resulting feature subset can be directly applied in downstream models, offering a more interpretable and stable basis for analysis compared to traditional selection techniques. We demonstrate the effectiveness of TangledFeatures on Alanine Dipeptide, applying it to the prediction of backbone torsional angles ϕ and ψ, and show that the selected features correspond to structurally meaningful intra-atomic distances that explain variation in these angles.

Proteins play a critical role in carrying out biological functions, and their 3D structures are essential in determining their functions. Accurately predicting the conformation of protein side-chains given their backbones is important for applications in protein structure prediction, design and protein-protein interactions.

Proteins play a critical role in carrying out biological functions, and their 3D structures are essential in determining their functions. Accurately predicting the conformation of protein side-chains given their backbones is important for applications in protein structure prediction, design and protein-protein interactions. Traditional methods are computationally intensive and have limited accuracy, while existing machine learning methods treat the problem as a regression task and overlook the restrictions imposed by the constant covalent bond lengths and angles. In this work, we present DiffPack, a torsional diffusion model that learns the joint distribution of side-chain torsional angles, the only degrees of freedom in side-chain packing, by diffusing and denoising on the torsional space. To avoid issues arising from simultaneous perturbation of all four torsional angles, we propose autoregressively generating the four torsional angles from \chi_1 to \chi_4 and training diffusion models for each torsional angle.

This complicates brute force approaches, making them virtually unfeasible for even moderately small molecules. In this paper we tackle the problem of generating conformers of a molecule in 3D space given Systematic methods, like OMEGA (Hawkins et al., 2010), its molecular graph. We parameterize these conformers offer rapid processing through rule-based generators and as continuous functions that map elements curated torsion templates. Despite their efficiency, these from the molecular graph to points in 3D models typically fail on complex molecules, as they often space. We then formulate the problem of learning overlook global interactions and are tricky to extend to to generate conformers as learning a distribution inputs like transition states or open-shell molecules. Classic over these functions using a diffusion generative stochastic methods, like molecular dynamics (MD) and model, called Molecular Conformer Fields Markov chain Monte Carlo (MCMC), rely on extensively exploring (MCF). Our approach is simple and scalable, and the energy landscape to find low-energy conformers.

The paper investigates a novel approach, based on Constraint Logic Programming (CLP), to predict potential 3D conformations of a protein via fragments assembly. The fragments are extracted and clustered by a preprocessor from a database of known protein structures. Assembling fragments into a complete conformation is modeled as a constraint satisfaction problem solved using CLP. The approach makes use of a simplified CA-side chain centroid protein model, that offers efficiency and a good approximation for space filling. The approach adapts existing energy models for protein representation and applies a large neighboring search (LNS) strategy. The results show the feasibility and efficiency of the method, and the declarative nature of the approach simplifies the introduction of additional knowledge and variations of the model.