OB Score

OB Score ranks protein targets by their likelihood of producing diffraction-quality crystals for high-throughput crystallography and structural genomics.

Key Features:

• Z-Score Scale: The OB-Score uses a Z-score scale to provide quantitative rankings of proteins' predicted propensity to yield diffraction-quality crystals.
• Predictive Matrix: A predictive matrix is derived from predicted isoelectric point and hydrophobicity values calculated against a background of nonredundant Protein Data Bank (PDB) entries solved at resolutions ≤3.0 Å using UniRef50 as a reference.
• Significant Differentiation: Application to TargetDB test datasets shows a highly significant difference in OB-Score distributions, indicating discriminative performance.
• Broad Applicability: Across 241 proteomes and within 7868 PfamA families, OB-Score values vary widely, with 73.4% of PfamA families containing at least one member with a high OB-Score.

Scientific Applications:

• Target selection and ranking: Guiding selection and ranking of protein targets for crystallography to improve success rates in high-throughput structural genomics.
• Prioritization for validation: Prioritizing proteins for experimental validation and accelerating the discovery of macromolecular structures.

Methodology:

Predicted isoelectric points and hydrophobicity values are calculated for proteins, a predictive matrix is derived from these parameters against a background of nonredundant PDB entries solved at ≤3.0 Å using UniRef50, scores are converted to a Z-score scale for ranking, and performance is evaluated on TargetDB test datasets.