禾谷镰孢FgCYP51B蛋白F511L突变对分生孢子产量及其对烯唑醇敏感性的影响

Effects of the F511L mutation in FgCYP51B of Fusarium graminearum on its conidial production and sensitivity to diniconazole

Phe511是禾谷镰孢甾醇-14α-脱甲基酶FgCYP51B活性口袋中的一个重要氨基酸。本研究中,我们探究了FgCYP51B蛋白中该位点突变后对禾谷镰孢主要生物学表型的影响,并通过分子对接探讨了可能的原因。结果表明禾谷镰孢FgCYP51B-F511L突变体在菌落形态、生长速率等表型上与野生型菌株PH-1没有明显差异。但是F511L突变导致分生孢子的产量严重降低,对烯唑醇的敏感性增强。分子对接发现突变后亮氨酸的长侧链使得烯唑醇的甲基发生扭转,侧链朝向发生改变,更有利于与蛋白受体形成较强的疏水作用,这可能是导致FgCYP51B-F511L突变体对烯唑醇敏感性增强的原因。

Phenylalanine 511 is an important amino acid residue in the active pocket of FgCYP51B,a sterol 14α-demethylase in Fusarium graminearum.In this study,we investigated the effect of the F511L mutation in FgCYP51B on its biological phenotypes.The results showed that the colony morphology and growth rate of the FgCYP51B-F511L mutant were consistent with those of the wild type strain PH-1.However,the F511L mutation led to significant reduction in conidia and increased sensitivity to diniconazole compared with the wild type strain.Molecular docking indicated that the F511L mutation made the methyl group of diniconazole twisted and changed the direction of the side chain of diniconazole,which facilitates strong hydrophobic interaction between diniconazole with the protein receptor.It may be the reason why FgCYP51B-F511L mutant is more sensitive to diniconazole than wild type strain.