Modeling functional changes to Escherichia coli thymidylate synthase upon single residue replacements: a...

Area of Science:

• Biochemistry
• Structural Biology
• Computational Biology

Background:

• Escherichia coli thymidylate synthase (TS) is crucial for DNA synthesis, making it a target for chemotherapy.
• Existing high-resolution X-ray structures and experimental mutagenesis data provide a foundation for computational studies.

Purpose of the Study:

• To investigate the impact of single amino acid substitutions on E. coli TS enzymatic activity using in silico mutagenesis.
• To establish a structure-function relationship for TS variants and develop predictive models for enzyme activity.

Main Methods:

• Employed an in silico mutagenesis technique utilizing the TS protein structure and a knowledge-based, four-body statistical potential.
• Calculated global and local structural perturbation scores for all single residue TS variants.
• Trained predictive models using feature vectors encoding mutated positions and neighboring residue environmental scores.

Main Results:

• Global perturbation scores effectively categorized residue positions based on their properties.
• A statistically significant structure-function relationship was identified for 372 experimentally characterized TS variants.
• Predictive models demonstrated the ability to forecast TS variant activity based on structural and environmental features.

Conclusions:

• In silico mutagenesis is a viable approach for predicting the functional impact of amino acid substitutions in TS.
• The study successfully elucidated structure-function relationships, offering insights for targeted drug design.
• Computational models can aid in understanding enzyme behavior and guiding future experimental investigations.