SCRWL

SCRWL predicts protein side-chain conformations for protein structure prediction and design and corresponds to SCWRL4.0.

Key Features:

• Backbone-dependent rotamer library: Uses a backbone-dependent rotamer library constructed using kernel density estimates.
• Conformation averaging: Averages over samples of conformations based on positions in the rotamer library to improve prediction reliability.
• Anisotropic hydrogen bonding function: Employs a fast anisotropic hydrogen bonding function to model directional hydrogen-bond interactions.
• Van der Waals interaction potential: Incorporates a short-range, soft van der Waals atom-atom interaction potential for realistic atomic interactions.
• Collision detection: Performs fast collision detection using k-discrete oriented polytopes.
• Tree decomposition algorithm: Uses a tree decomposition algorithm to solve the combinatorial side-chain placement problem.
• Parameter optimization in crystal environment: Optimizes parameters by determining the interaction graph within the crystal environment using symmetry operators from the crystallographic space group.

Scientific Applications:

• Homology modeling: Predicts side-chain conformations to support accurate homology model refinement.
• Protein design: Provides side-chain conformations used in computational protein design and engineering.
• Benchmarking/Validation: Validated on a testing set of 379 proteins, correctly predicting 86% of chi(1) angles and 75% of chi(1+2) angles within 40 degrees of X-ray positions, increasing to 89% and 80% respectively for side chains in the 25–100th electron density percentile.

Methodology:

Backbone-dependent rotamer library constructed with kernel density estimates; conformation averaging over rotamer samples; fast anisotropic hydrogen-bonding function; short-range soft van der Waals atom-atom potential; collision detection via k-discrete oriented polytopes; tree decomposition algorithm for combinatorial optimization; parameter optimization via interaction graph determination using crystallographic space-group symmetry operators.