Sequence-, structure-, and dynamics-based comparisons of structurally homologous CheY-like proteins

Area of Science:

• Biochemistry
• Structural Biology
• Bioinformatics

Background:

• Response regulators like CheY, NT-NtrC, and Spo0F are crucial in bacterial signal transduction.
• These proteins share functional and structural similarities but exhibit low sequence identity, posing a challenge for traditional comparison methods.

Purpose of the Study:

• To apply the novel property factor method (PFM) for physically based sequence comparison.
• To investigate subtle sequence differences in bacterial response regulators (CheY, NT-NtrC, Spo0F) not detectable by conventional alignment.

Main Methods:

• Property Factor Method (PFM) for sequence comparison.
• Distance matrix comparisons to correlate sequence differences with structural characteristics.
• Molecular dynamics simulations at various temperatures.
• Comparison with experimentally determined B factors and Gaussian network model predictions.

Main Results:

• PFM identified a statistically significant qualitative difference between CheY and the other two proteins.
• Sequence differences align with structural characteristics and native contact distributions during unfolding.
• Molecular dynamics simulations predicted distinct dynamic properties for CheY compared to NT-NtrC and Spo0F.
• PFM results are consistent with experimental data and other simulation models.

Conclusions:

• The PFM approach can detect physical sequence differences missed by traditional alignment methods.
• This physically based method provides a more nuanced understanding of protein sequence-structure-dynamics relationships.
• PFM enhances the analysis of functionally similar but divergent protein families.