Automated sequence-specific NMR assignment of homologous proteins using the program GARANT

Area of Science:

• Structural Biology
• Computational Chemistry
• Biophysics

Background:

• Automated nuclear magnetic resonance (NMR) assignment is crucial for protein structure determination.
• The GARANT (General Algorithm for Resonance AssignmeNT) program facilitates sequence-specific NMR assignment.
• Extending GARANT's utility to homologous proteins requires leveraging existing structural or chemical shift data.

Purpose of the Study:

• To demonstrate the effectiveness of the GARANT program for NMR assignment of homologous proteins.
• To showcase the integration of 3D structural information and parent protein chemical shifts into the assignment process.
• To validate GARANT's performance across diverse protein systems and NMR data types.

Main Methods:

• Utilizing the GARANT program for automated NMR assignment.
• Incorporating interatomic distances from 3D structures to predict Nuclear Overhauser Effects (NOEs).
• Employing chemical shifts from homologous proteins to refine peak position predictions.

Main Results:

• Successful application of GARANT to three distinct proteins: Tendamistat mutant, Antp homeodomain mutant, and free cyclophilin A.
• Achieved nearly complete assignment of polypeptide backbone resonances in all tested systems.
• Obtained assignment of over 80% of amino acid side-chain resonances without manual intervention.

Conclusions:

• GARANT effectively assigns homologous proteins by integrating structural or chemical shift data.
• The program significantly reduces manual effort in NMR assignment, achieving high accuracy.
• GARANT represents a powerful tool for accelerating protein structure-based research.