Structural insights into the substrate binding of phosphomevalonate kinase from the silkworm, Bombyx mori.
Structural insights into the substrate binding of phosphomevalonate kinase from the silkworm, Bombyx mori.
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DOI：
10.1016/j.ibmb.2022.103849
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发表时间：
2022-10
影响因子：
3.8
通讯作者：
Hua Zhang;Jie Liu;Hanlin Wang;H. Fang;P. Zhao;Q. Xia;P. Guo
中科院分区：
文献类型：
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作者：
Hua Zhang;Jie Liu;Hanlin Wang;H. Fang;P. Zhao;Q. Xia;P. Guo
磷酸甲羟戊酸激酶（PMK）是参与保幼激素（JH）生物合成途径的重要酶，在甲羟戊酸途径中催化甲羟戊酸5-磷酸磷酸化为甲羟戊酸5-二磷酸。在此，我们以 1.60 Å 的分辨率报道了来自家蚕 (Bombyx mori) 的昆虫 PMK (BmPMK) 的晶体结构。 BmPMK的整体结构采用紧凑的α/β构象，由核心区和盖区两部分组成。芯和盖区域之间的界面形成连续且带负电的凹槽以容纳基板。利用计算模拟结合定点突变和生化分析，我们定义了BmPMK与辅因子和底物的结合模式，为理解PMK的催化机制和抑制剂的设计提供了结构基础。此外，以甲羟戊酸 5-磷酸为底物，BmPMK 在 pH 8.0 时表现出最佳酶活性，最适温度为 30 °C。 BmPMK 的表达谱和动力学分析表明它在控制家蚕 JH 生物合成中发挥着关键作用。总的来说，这些发现让人们更好地了解昆虫 PMK 的结构和生化特征。
Phosphomevalonate kinase (PMK) is an important enzyme involved in the juvenile hormone (JH) biosynthesis pathway that catalyzes the phosphorylation of mevalonate 5-phosphate into mevalonate 5-diphosphate in the mevalonate pathway. Herein, we report the crystal structure of insect PMK fromBombyx mori(BmPMK) at a resolution of 1.60 Å. The overall structure of BmPMK adopts a compact α/β conformation with two parts: the core and lid regions. The interface between the core and lid regions forms a continuous and negatively charged groove to accommodate the substrates. Using computational simulation combined with site-directed mutagenesis and biochemical analysis, we define the binding mode of BmPMK with the cofactor and the substrate, which provides a structural basis for understanding the catalytic mechanism and the design of inhibitors of PMK. Moreover, BmPMK showed the optimal enzyme activity at pH 8.0, and the optimal temperature was 30 °C, using mevalonate 5-phosphate as the substrate. The expression profiles and kinetic analyses of BmPMK indicated that it plays critical role in the control of JH biosynthesis in silkworms. Collectively, these findings provide a better understanding of the structural and biochemical features of insect PMK.