Related Experiment Video
Updated: Jul 5, 2025
Removal of an Internal Translational Start Site from mRNA While Retaining Expression of the Full-Length Protein
Published on: March 16, 2022
Characterizing the Molecular Mechanism of the Lethal C423D Mutation in FgMyoI: A Molecular Perspective
Yiqiong Bao1, Fangying Jia2, Mengrong Li1
1College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Abstract:
The lethal mutation C423D in Fusarium graminearum myosin I (FgMyoI) occurs close to the binding pocket of the allosteric inhibitor phenamacril and causes severe inhibition on mycelial growth of F. graminearum strain PH-1. Here, based on extensive Gaussian accelerated molecular dynamics simulations and wet experiments, we elucidate the underlying molecular mechanism of the abnormal functioning of the FgMyoIC423D mutant at the atomistic level. Our results suggest that the damaging mutation C423D exhibits a synergistic allosteric inhibition mechanism similar to but more robust than that of phenamacril, including effects on the active site and actin binding. Unlike phenamacril-induced closure of Switch2, the mutation results in unfolding of the N-terminal relay helix with a partially opened Switch2 and blocks the structural rearrangement of the relay/SH1 helices, impairing the proper initiation of the recovery stroke. Due to the significant influence of C423D mutation on the function of FgMyoI, designing covalent inhibitors targeting this site holds tremendous potential.
Insights
The C423D mutation in Fusarium graminearum myosin I (FgMyoI) severely inhibits fungal growth by disrupting its structure and function. This mutation offers a robust allosteric inhibition mechanism, suggesting potential for new antifungal drug development.
Area of Science:
- Mycology
- Molecular Biology
- Biochemistry
Background:
- The C423D mutation in Fusarium graminearum myosin I (FgMyoI) is a lethal mutation that inhibits mycelial growth.
- FgMyoI is crucial for the growth of F. graminearum strain PH-1.
- The mutation's proximity to the phenamacril binding pocket suggests allosteric inhibition.
Purpose of the Study:
- To elucidate the molecular mechanism of the C423D FgMyoI mutant's abnormal functioning.
- To understand the atomistic-level effects of the C423D mutation on FgMyoI.
- To explore the potential for designing new inhibitors based on the mutation's effects.
Main Methods:
- Gaussian accelerated molecular dynamics simulations.
- Wet experiments.
- Atomistic-level analysis of protein structure and function.
Main Results:
- The C423D mutation induces a synergistic allosteric inhibition mechanism, more potent than phenamacril.
- The mutation affects the active site and actin binding of FgMyoI.
- It causes unfolding of the N-terminal relay helix, partial Switch2 opening, and blocks relay/SH1 helix rearrangement, impairing the recovery stroke.
Conclusions:
- The C423D mutation significantly impacts FgMyoI function, leading to severe growth inhibition.
- The mutation's mechanism is similar to, but more robust than, phenamacril.
- Targeting this mutation site with covalent inhibitors presents a promising strategy for developing new antifungal agents.
