STAP

STAP refines NMR solution structures using statistical torsion angle potentials (STAP) within a simulated annealing protocol to improve the quality and structural-analysis suitability of 2,405 PDB-derived NMR entries.

Key Features:

• Database Content: The public database contains 2,405 refined NMR structures sourced from the Protein Data Bank (PDB).
• Refinement Protocol: A simulated annealing protocol integrates statistical torsion angle potentials (STAP) and newly developed knowledge-based potentials during refinement.
• Quality Indicators: Structures were evaluated using nuclear Overhauser effect (NOE) completeness, Ramachandran plot appearance, χ(1)-χ(2) rotamer normality, and protein stability–related parameters.
• Quality Improvement: Inclusion of STAP produced significant improvements across most assessed quality metrics, increasing reliability for structural analysis.

Scientific Applications:

• NMR structure curation: Provides higher-quality NMR ensembles for downstream structural analysis and comparative studies.
• Validation and benchmarking: Supports development and benchmarking of validation tools and scoring functions for NMR structures.
• Structural modeling and interpretation: Enables improved modeling, interpretation, and comparison of NMR-derived structures with high-resolution X-ray data.
• Methodological research: Facilitates studies addressing limitations of NMR-derived structures and testing refinement strategies.

Methodology:

The refinement process uses a simulated annealing protocol that integrates statistical torsion angle potentials (STAP) as knowledge-based potentials to target improved structural potentials.