Structural and Functional Studies of H. seropedicae RecA Protein - Insights into the Polymerization of RecA Protein as Nucleoprotein Filament.
Structural and Functional Studies of H. seropedicae RecA Protein - Insights into the Polymerization of RecA Protein as Nucleoprotein Filament.
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血清多乳杆菌RECA蛋白的结构和功能研究 - 对RECA蛋白作为核蛋白丝的聚合的见解。
DOI：
10.1371/journal.pone.0159871
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Cox MM
中科院分区：
文献类型：
--
作者：
Leite WC;Galvão CW;Saab SC;Iulek J;Etto RM;Steffens MB;Chitteni-Pattu S;Stanage T;Keck JL;Cox MM
细菌RecA蛋白在DNA损伤修复的复杂系统中发挥作用。在此，我们报道了seropedicae Herbaspirillum RecA蛋白（HsRecA）的功能和结构特征。与大肠杆菌RecA蛋白相比，HsRecA蛋白更有效地将SSB蛋白从ssDNA中取代。HsRecA还能更有效地促进DNA链交换。HsRecA-ADP/ATP配合物的三维结构已被求解到1.7 Å分辨率。HsRecA蛋白含有一个小的n端结构域、一个中央核心atp酶结构域和一个大的c端结构域，与细菌的同源RecA蛋白相似。比较结构分析表明，细菌RecAs中也存在古细菌和真核生物RecA家族蛋白的n端聚合基元。从HsRecA-ADP/ATP的六聚体结构中重建的静电电位显示，沿着丝的内侧，ssDNA被结合在丝的内部，有一个高正电荷。相对于EcRecA，该表面的特性可以解释HsRecA蛋白结合ssDNA的更大能力，形成一个连续的核蛋白丝，取代SSB并促进DNA交换。我们的功能和结构分析提供了深入了解细菌RecA作为螺旋核蛋白丝聚合的分子机制。
The bacterial RecA protein plays a role in the complex system of DNA damage repair. Here, we report the functional and structural characterization of the Herbaspirillum seropedicae RecA protein (HsRecA). HsRecA protein is more efficient at displacing SSB protein from ssDNA than Escherichia coli RecA protein. HsRecA also promotes DNA strand exchange more efficiently. The three dimensional structure of HsRecA-ADP/ATP complex has been solved to 1.7 Å resolution. HsRecA protein contains a small N-terminal domain, a central core ATPase domain and a large C-terminal domain, that are similar to homologous bacterial RecA proteins. Comparative structural analysis showed that the N-terminal polymerization motif of archaeal and eukaryotic RecA family proteins are also present in bacterial RecAs. Reconstruction of electrostatic potential from the hexameric structure of HsRecA-ADP/ATP revealed a high positive charge along the inner side, where ssDNA is bound inside the filament. The properties of this surface may explain the greater capacity of HsRecA protein to bind ssDNA, forming a contiguous nucleoprotein filament, displace SSB and promote DNA exchange relative to EcRecA. Our functional and structural analyses provide insight into the molecular mechanisms of polymerization of bacterial RecA as a helical nucleoprotein filament.