Location and architecture of the Caulobacter crescentus chemoreceptor array
Location and architecture of the Caulobacter crescentus chemoreceptor array
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DOI：
10.1111/j.1365-2958.2008.06219.x
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发表时间：
2008-07-01
影响因子：
3.6
通讯作者：
Jensen, Grant J.
中科院分区：
文献类型：
--
作者：
Briegel, Ariane;Ding, H. Jane;Jensen, Grant J.
发展了一种记录小细菌细胞荧光和冷冻-EM图像的新方法，并将其用于识别完整的新月藻细胞冷冻断层图像中的化学感受器阵列。我们发现，在保存在近自然状态下的野生型细胞中，化学感受器以12 nm的晶格间距六边形排列，距离它们控制的鞭毛马达只有几十纳米。这些排列总是在细胞的凸面上发现的，进一步表明Caulbacter细胞保持背侧/腹侧和前侧/后部的不对称性。将已知的受体二聚体三聚体的晶体结构放置在晶格的每个顶点上，很好地解释了密度，并符合其他限制条件。根据这种受体排列模型，每个阵列有一千到两千个受体。
A new method for recording both fluorescence and cryo-EM images of small bacterial cells was developed and used to identify chemoreceptor arrays in cryotomograms of intact Caulobacter crescentus cells. We show that in wild-type cells preserved in a near-native state, the chemoreceptors are hexagonally packed with a lattice spacing of 12 nm, just a few tens of nanometers away from the flagellar motor that they control. The arrays were always found on the convex side of the cell, further demonstrating that Caulobacter cells maintain dorsal/ventral as well as anterior/posterior asymmetry. Placing the known crystal structure of a trimer of receptor dimers at each vertex of the lattice accounts well for the density and agrees with other constraints. Based on this model for the arrangement of receptors, there are between one and two thousand receptors per array.