An ensemble of lipoxygenase structures reveals novel conformations of the Fe coordination sphere.
An ensemble of lipoxygenase structures reveals novel conformations of the Fe coordination sphere.
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脂氧合酶结构的集合揭示了 Fe 配位球的新构象。
DOI：
10.1002/pro.3602
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Newcomer,MarciaE
中科院分区：
文献类型：
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作者：
Pakhomova,Svetlana;Boeglin,WilliamE;Neau,DavidB;Bartlett,SueG;Brash,AlanR;Newcomer,MarciaE
脂氧合酶（LOX）催化了多不饱和脂肪酸的区域和立体特异性氧合；铁和锰两种形式的酶已被描述。铁和锰配位球的结构元素和金属中心所在的螺旋催化结构域高度保守。然而，动物、植物和微生物的LOX各有不同的特征。我们报道了真菌植物致病菌禾谷镰刀菌LOX的5个晶体结构。这种LOX显示了一种新的氨基末端扩展，为二聚化提供了一个包裹结构域。此外，这种延伸似乎干扰了铁配位球，因为当酶是二聚体时，在催化金属上没有观察到典型的LOX结构。相反，新的四坐标、五坐标和六坐标Fe2+连接是显而易见的。相反，单体结构表明，随着氨基末端段的重新定位，酶可以具有典型的Fe2+配位球的生产构象。
The regio‐ and stereo‐specific oxygenation of polyunsaturated fatty acids is catalyzed by lipoxygenases (LOX); both Fe and Mn forms of the enzyme have been described. Structural elements of the Fe and Mn coordination spheres and the helical catalytic domain in which the metal center resides are highly conserved. However, animal, plant, and microbial LOX each have distinct features. We report five crystal structures of a LOX from the fungal plant pathogenFusarium graminearum. This LOX displays a novel amino terminal extension that provides a wrapping domain for dimerization. Moreover, this extension appears to interfere with the iron coordination sphere, as the typical LOX configuration is not observed at the catalytic metal when the enzyme is dimeric. Instead novel tetra‐, penta‐, and hexa‐coordinate Fe2+ligations are apparent. In contrast, a monomeric structure indicates that with repositioning of the amino terminal segment, the enzyme can assume a productive conformation with the canonical Fe2+coordination sphere.