Protein design by fusion: implications for protein structure prediction and evolution

Area of Science:

• Structural biology
• Computational biology
• Protein engineering

Background:

• Domain fusion is a valuable technique in protein design.
• Heterodimeric proteins, like flagella assembly proteins FliS and FliC, present unique structural challenges.
• Accurate protein structure prediction is crucial for protein design and engineering.

Purpose of the Study:

• To report the structure of a fusion protein combining FliS and FliC.
• To evaluate the accuracy of threading-based structural prediction methods for fused heterodimers.
• To identify naturally occurring heterodimers to inform protein design and prediction.

Main Methods:

• X-ray crystallography was used to determine the structure of the FliS-FliC fusion protein.
• Threading-based computational methods were employed to predict the structure of the fusion protein.
• Bioinformatic analysis was performed to identify homologous naturally occurring heterodimers.

Main Results:

• The structure of the FliS-FliC heterodimeric fusion protein was successfully determined.
• Threading-based predictions did not accurately model the fused heterodimer structure.
• Naturally occurring heterodimers homologous to full-length proteins were identified.

Conclusions:

• The designed FliS-FliC fusion protein demonstrates the potential of domain fusion in protein engineering.
• Current threading-based prediction tools require refinement to accurately model fused heterodimeric proteins.
• Naturally occurring heterodimeric structures offer valuable insights for improving protein structure prediction algorithms.