Low resolution structure of the σ54 transcription factor revealed by x-ray solution scattering
Low resolution structure of the σ54 transcription factor revealed by x-ray solution scattering
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DOI：
10.1074/jbc.275.6.4210
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发表时间：
2000-02-11
影响因子：
4.8
通讯作者：
Buck, M
中科院分区：
文献类型：
--
作者：
Svergun, DI;Malfois, M;Buck, M
sigma 54 RNA 聚合酶全酶在增强子依赖性转录中发挥作用。通过同步加速器 X 射线散射分析溶液中细菌 RNA 聚合酶 sigma 54 亚基的结构组织。从全长蛋白质和能够结合核心 RNA 聚合酶的大片段收集散射图案，并使用两种从头开始形状测定技术恢复它们的低分辨率形状。 sigma 54 亚基是高度伸长的颗粒，核心结合片段可以明确定位在全长蛋白质内部。核心结合片段的回飞镖状形状与大肠杆菌 sigma 70 蛋白片段的原子模型相似，表明虽然 sigma 54 和 sigma 70 因子在一级序列上不相关，但它们可能具有一些结构相似性。通过与 sigma 54 核心结合片段进行比较，还预测了 sigma 54 的潜在 DNA 结合表面。
The sigma 54 RNA polymerase holoenzyme functions in enhancer-dependent transcription. The structural organization of the sigma 54 subunit of bacterial RNA polymerase in solution is analyzed by synchrotron x-ray scattering. Scattering patterns are collected from the full-length protein and from a large fragment able to bind the core RNA polymerase, and their low resolution shapes are restored using two ab initio shape determination techniques. The sigma 54 subunit is a highly elongated particle, and the core binding fragment can be unambiguously positioned inside the full-length protein. The boomerang-like shape of the core binding fragment is similar to that of the atomic model of a fragment of the Escherichia coli sigma 70 protein, indicating that, although the sigma 54 and sigma 70 factors are unrelated by primary sequence, they may share some structural similarity. Potential DNA binding surfaces of sigma 54 are also predicted by comparison with the sigma 54 core binding fragment.