Self-polymerization of archaeal RadA protein into long and fine helical filaments
Self-polymerization of archaeal RadA protein into long and fine helical filaments
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DOI：
10.1016/j.bbrc.2004.08.163
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发表时间：
2004-10-22
影响因子：
3.1
通讯作者：
Wang, TF
中科院分区：
文献类型：
--
作者：
Lee, MH;Leng, CH;Wang, TF
古细菌蛋白 RadA 是 RecA/Rad51 同源物，能够促进 DNA 链与同源序列的配对和交换。在这里，我们表达、纯化并结晶了来自硫磺硫化叶菌 (Sso) 的催化活性 RadA 蛋白。初步 X 射线分析表明，Sso RadA 蛋白可能在蛋白晶体中形成螺旋丝。使用带有碳纳米管 (CNT) 尖端的原子力显微镜进行高分辨率成像，我们证明 Sso RadA 蛋白确实在缺乏 DNA 和核苷酸辅因子的情况下形成长度达 1 微米（类似于 10 纳米螺距）的细螺旋丝。我们还观察到Sso RadA蛋白螺旋丝在与ssDNA一起孵育时可以分解，然后蛋白质与ssDNA结合形成核蛋白丝。 (C) 2004 Elsevier Inc. 保留所有权利。
The Archaeal protein RadA, a RecA/Rad51 homolog, is able to promote pairing and exchange of DNA strands with homologous sequences. Here, we have expressed, purified, and crystallized the catalytically active RadA protein from Sulfolobus solfataricus (Sso). Preliminary X-ray analysis indicated that Sso RadA protein likely forms helical filament in protein crystals. Using atomic force microscopy with a carbon nanotube (CNT) tip for high-resolution imaging, we demonstrated that Sso RadA protein indeed forms fine helical filaments up to 1 mum in length (similar to10 nm pitch) in the absence of DNA and nucleotide cofactor. We also observed that Sso RadA protein helical filament could dissemble upon incubation with ssDNA, and then the proteins associate with ssDNA to form nucleoprotein filament. (C) 2004 Elsevier Inc. All rights reserved.