Fusarium is a genus of filamentous fungi that includes species that cause devastating diseases in major staple crops, such as wheat, maize, rice, and barley, resulting in severe yield losses and mycotoxin contamination of infected grains. Phenamacril is a novel fungicide that is considered environmentally benign due to its exceptional specificity; it inhibits the ATPase activity of the sole class I myosin of only a subset of Fusarium species including the major plant pathogens F. graminearum, F. asiaticum and F. fujikuroi. To understand the underlying mechanisms of inhibition, species specificity, and resistance mutations, we have determined the crystal structure of phenamacril-bound F. graminearum myosin I. Phenamacril binds in the actin-binding cleft in a new allosteric pocket that contains the central residue of the regulatory Switch 2 loop and that is collapsed in the structure of a myosin with closed actin-binding cleft, suggesting that pocket occupancy blocks cleft closure. We have further identified a single, transferable phenamacril-binding residue found exclusively in phenamacril-sensitive myosins to confer phenamacril selectivity.

镰刀菌是丝状真菌的属，其包括在主要主食作物如小麦，玉米，水稻和大麦中引起破坏性疾病的物种，导致严重的产量损失和受感染谷物的霉菌毒素污染。苯那那利是一种新型杀菌剂，由于其卓越的特异性而被认为对环境无害。它抑制镰刀菌（Fusarium）物种（包括主要植物病原体F）的唯一I类肌球蛋白的ATPase活性。小麦赤霉病，˚F。和黄龙病˚F。富士黑井。为了了解抑制，物种特异性和抗性突变的潜在机制，我们确定了苯甲丙烯酰胺结合的F的晶体结构。禾本科肌球蛋白I.苯那莫瑞在新的变构口袋中的肌动蛋白结合裂隙中结合，该变构口袋包含调节性Switch 2环的中央残基，并在具有封闭的肌动蛋白结合裂隙的肌球蛋白的结构中塌陷，表明口袋占用块closure裂闭合。我们进一步鉴定了仅在对苯甲酰胺敏感的肌球蛋白中发现的单个可转移的苯甲酰胺结合残基，以赋予苯甲酰胺选择性。