In vivo structure of the E. coli FtsZ-ring revealed by photoactivated localization microscopy (PALM).
In vivo structure of the E. coli FtsZ-ring revealed by photoactivated localization microscopy (PALM).
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DOI：
10.1371/journal.pone.0012680
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发表时间：
2010-09-13
期刊：
影响因子：
3.7
通讯作者：
Xiao J
中科院分区：
文献类型：
--
作者：
Fu G;Huang T;Buss J;Coltharp C;Hensel Z;Xiao J
FtsZ 蛋白是一种微管蛋白样 GTP 酶，在原核细胞分裂中发挥着关键作用。在体内，它定位于中细胞并组装成环状结构——Z环。 Z 环作为招募所有其他分裂蛋白并产生胞质分裂的收缩力的重要支架，但其超分子结构仍然未知。由于细菌细胞的细胞质致密，电子显微镜 (EM) 未能成功检测 Z 环，而传统的荧光光学显微镜 (FLM) 由于光的衍射，只能提供有限空间分辨率 (200–300 nm) 的图像。因此，考虑到细菌细胞的尺寸较小，识别 Z 形环的体内结构提出了巨大的挑战。在这里，我们使用光激活定位显微镜（PALM），一种基于单分子的超分辨率成像技术，来表征大肠杆菌中 Z 环的体内结构。我们实现了约 35 nm 的空间分辨率，并发现除了预期的环状构象外，大肠杆菌的 Z 环还采用了一种新颖的压缩螺旋构象，具有可变的螺旋长度和螺距。我们测量到 Z 环的厚度约为 110 nm，Z 环内 FtsZ 分子的堆积密度大于单层扁平带结构的预期值。我们的结果强烈表明，Z 环由松散的 FtsZ 原丝束组成，这些原丝在细胞的纵向和径向方向上彼此随机重叠。我们的结果提供了对 Z 环空间组织的重要见解，并为进一步研究 Z 环的结构-功能关系和细胞周期依赖性调节打开了大门。
The FtsZ protein, a tubulin-like GTPase, plays a pivotal role in prokaryotic cell division. In vivo it localizes to the midcell and assembles into a ring-like structure-the Z-ring. The Z-ring serves as an essential scaffold to recruit all other division proteins and generates contractile force for cytokinesis, but its supramolecular structure remains unknown. Electron microscopy (EM) has been unsuccessful in detecting the Z-ring due to the dense cytoplasm of bacterial cells, and conventional fluorescence light microscopy (FLM) has only provided images with limited spatial resolution (200–300 nm) due to the diffraction of light. Hence, given the small sizes of bacteria cells, identifying the in vivo structure of the Z-ring presents a substantial challenge. Here, we used photoactivated localization microscopy (PALM), a single molecule-based super-resolution imaging technique, to characterize the in vivo structure of the Z-ring in E. coli. We achieved a spatial resolution of ∼35 nm and discovered that in addition to the expected ring-like conformation, the Z-ring of E. coli adopts a novel compressed helical conformation with variable helical length and pitch. We measured the thickness of the Z-ring to be ∼110 nm and the packing density of FtsZ molecules inside the Z-ring to be greater than what is expected for a single-layered flat ribbon configuration. Our results strongly suggest that the Z-ring is composed of a loose bundle of FtsZ protofilaments that randomly overlap with each other in both longitudinal and radial directions of the cell. Our results provide significant insight into the spatial organization of the Z-ring and open the door for further investigations of structure-function relationships and cell cycle-dependent regulation of the Z-ring.
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影响因子：
48
作者：
Biteen, Julie S.;Thompson, Michael A.;Tselentis, Nicole K.;Bowman, Grant R.;Shapiro, Lucy;Moerner, W. E.
通讯作者：
Moerner, W. E.
影响因子：
64.8
作者：
DEBOER, P;CROSSLEY, R;ROTHFIELD, L
通讯作者：
ROTHFIELD, L
影响因子：
3.6
作者：
Aarsman, MEG;Piette, A;den Blaauwen, T
通讯作者：
den Blaauwen, T
影响因子：
1.6
作者：
Geisbrecht, BV;Bouyain, S;Pop, M
通讯作者：
Pop, M
影响因子：
3.2
作者：
Anderson, DE;Gueiros-Filho, FJ;Erickson, HP
通讯作者：
Erickson, HP