Pairwise covariance adds little to secondary structure prediction but improves the prediction of non-canonical local structure
2008

Improving Protein Structure Prediction with Pairwise Covariance

Sample size: 559 publication Evidence: moderate

Author Information

Author(s): Christopher Bystroff, Bobbie-Jo Webb-Robertson

Primary Institution: Rensselaer Polytechnic Institute

Hypothesis

Can pairwise covariant sequence models improve the prediction of protein local structures compared to profile-based models?

Conclusion

Pairwise covariance improves the prediction of certain loop motifs but does not significantly enhance the prediction of alpha helices or beta strands.

Supporting Evidence

  • Pairwise covariances were shown to be statistically robust in cross-validation tests.
  • The study found that reducing the amino acid alphabet to nine classes was critical for statistical significance.
  • Improvements in local structure prediction were observed when covariance was added to the profile model.

Takeaway

This study looks at how well we can guess the shapes of proteins based on their building blocks, and it finds that looking at pairs of building blocks helps with some shapes but not all.

Methodology

The study used a modified I-sites motif library with pairwise covariance metrics to predict local protein structures and evaluated the predictions on a test set of proteins.

Limitations

The study found that while pairwise covariance improved predictions for non-canonical structures, it did not significantly enhance predictions for canonical secondary structures.

Statistical Information

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1471-2105-9-429

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