Structure of the Bacillus subtilis hibernating 100S ribosome reveals the basis for 70S dimerization
Structure of the Bacillus subtilis hibernating 100S ribosome reveals the basis for 70S dimerization
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DOI：
10.15252/embj.201696189
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发表时间：
2017-07-14
期刊：
影响因子：
11.4
通讯作者：
Wilson, Daniel N.
中科院分区：
文献类型：
--
作者：
Beckert, Bertrand;Abdelshahid, Maha;Wilson, Daniel N.
在营养剥夺等胁迫条件下，细菌进入冬眠阶段，冬眠阶段的特征是出现100S核糖体颗粒。在大肠杆菌中，70S核糖体二聚化成100S需要核糖体调节因子（RMF）和冬眠促进因子（HPF）的作用。大多数其他细菌缺乏RMF，而是含有长形式的HPF (LHPF)，这是形成100S所必需和充分的。虽然存在一些关于RMF和HPF如何介导大肠杆菌1000s （Ec100S）形成的结构信息，但LHPF对1000s形成的结构见解迄今为止还缺乏。在这里，我们展示了枯草芽孢杆菌冬眠的100S （Bs100S）的低温电镜结构，揭示了LHPF的c端结构域（CTD）占据了与RMF不同的30S平台上的一个位点。此外，与RMF不同，BsHPF-CTD直接参与二聚体界面的形成，从而说明了与一些c-变形菌（如大肠杆菌）相比，大多数含有LHPF的细菌介导100S形成的不同机制。
Under stress conditions, such as nutrient deprivation, bacteria enter into a hibernation stage, which is characterized by the appearance of 100S ribosomal particles. In Escherichia coli, dimerization of 70S ribosomes into 100S requires the action of the ribosome modulation factor (RMF) and the hibernation-promoting factor (HPF). Most other bacteria lack RMF and instead contain a long form HPF (LHPF), which is necessary and sufficient for 100S formation. While some structural information exists as to how RMF and HPF mediate formation of E. coli 100S (Ec100S), structural insight into 100S formation by LHPF has so far been lacking. Here we present a cryo-EM structure of the Bacillus subtilis hibernating 100S (Bs100S), revealing that the C-terminal domain (CTD) of the LHPF occupies a site on the 30S platform distinct from RMF. Moreover, unlike RMF, the BsHPF-CTD is directly involved in forming the dimer interface, thereby illustrating the divergent mechanisms by which 100S formation is mediated in the majority of bacteria that contain LHPF, compared to some c-proteobacteria, such as E. coli.