Structure of a P element transposase-DNA complex reveals unusual DNA structures and GTP-DNA contacts
Structure of a P element transposase-DNA complex reveals unusual DNA structures and GTP-DNA contacts
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DOI：
10.1038/s41594-019-0319-6
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发表时间：
2019-11-01
影响因子：
16.8
通讯作者：
Rio, Donald C.
中科院分区：
文献类型：
--
作者：
Ghanim, George E.;Kellogg, Elizabeth H.;Rio, Donald C.
P元素转座酶催化P元素DNA转座子在果蝇基因组中的移动。P元件转座酶表现出一些独特的性质，包括需要一个三磷酸鸟苷辅助因子，以及在转座过程中产生长时间交错的DNA断裂。为了深入了解这些特征，我们用冷冻EM测定了果蝇P元素转座酶链转移复合体的原子结构。这个转座后核蛋白复合体的结构表明，末端单链转座子DNA采用了不寻常的A型和扭曲的B型螺旋几何结构，这是由广泛的蛋白质-DNA相互作用稳定的。此外，我们推测结合的鸟苷三磷酸辅助因子与转座子DNA的末端碱基相互作用，显然是为了定位P元件DNA进行催化。我们的结构提供了P元素转座酶超家族的第一个视角，为P元素转座提供了新的见解，并暗示了一条与其他剪切粘贴DNA转座酶根本不同的转座途径。
P element transposase catalyzes the mobility of P element DNA transposons within the Drosophila genome. P element transposase exhibits several unique properties, including the requirement for a guanosine triphosphate cofactor and the generation of long staggered DNA breaks during transposition. To gain insights into these features, we determined the atomic structure of the Drosophila P element transposase strand transfer complex using cryo-EM. The structure of this post-transposition nucleoprotein complex reveals that the terminal single-stranded transposon DNA adopts unusual A-form and distorted B-form helical geometries that are stabilized by extensive protein-DNA interactions. Additionally, we infer that the bound guanosine triphosphate cofactor interacts with the terminal base of the transposon DNA, apparently to position the P element DNA for catalysis. Our structure provides the first view of the P element transposase superfamily, offers new insights into P element transposition and implies a transposition pathway fundamentally distinct from other cut-and-paste DNA transposases.