Uncovering the Differed Susceptibility of Fusarium oxysporum ( Fo32931 and FocII5 ) to Fungicide Phenamacril: From Computational and Experimental Perspectives

作者：Yiqiong Bao, Fangying Jia, Y. H. Geng, Guohong Song, Ran Xu, Hancheng Wang, Yuguang Mu, Henry H. Y. Tong, Feng Zhang, Jingjing Guo · 发表于：Journal of Agricultural and Food Chemistry · 年份：2024 · DOI：10.1021/acs.jafc.4c07865 · 被引用次数：3 · 研究领域：Fungal Plant Pathogen Control、Mycotoxins in Agriculture and Food、Plant Disease Resistance and Genetics

Fo32931 and FoCII5 are two subtypes of Fusarium oxysporum (Fo), a pathogenic filamentous fungus. Phenamacril (PHA), a Fusarium -specific fungicide that targets myosin I, exhibits significant hyphal growth inhibition in Fo32931 but shows weak resistance in FocII5, despite only two amino acid differences in the PHA-binding pocket of myosin I. In this study, we aim to elucidate the molecular basis for the differential sensitivity of F. oxysporum myosin I variants (FoMyoI 32931 and FoMyoI cII5 ) to phenamacril through computational methods and biochemical validation. The results suggest that phenamacril functions as an allosteric inhibitor for FoMyoI 32931, inhibiting the large oscillation of the converter lever domain (CLD) upon ATP binding and promoting the opening of the outer cleft, further impairing protein function. PHA significantly reduced the coupling between the CLD, especially the converter, and the catalytic center, diminishing the response of the CLD to the motor domain in FoMyoI 32931 . From the residue mutation experiment, we found that the S418T substitution in FoMyoI cII5 is the key to the reduced phenamacril sensitivity of FocII5 . According to the microscale thermophoresis (MST) assay and pocket conformation analysis, the S418T mutation disturbs the orientation of pocket residues, especially Lys537, leading to a looser pocket and reduced interaction between Lys537 and phenamacril, which lowers the binding affinity of FoMyoI cII5 for phenamacril. These findings ...