Anthrax toxin translocation complex reveals insight into the lethal factor unfolding and refolding mechanism.
Anthrax toxin translocation complex reveals insight into the lethal factor unfolding and refolding mechanism.
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DOI：
10.1038/s41598-021-91596-3
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发表时间：
2021-06-22
影响因子：
4.6
通讯作者：
Freudenthal BD
中科院分区：
文献类型：
--
作者：
Machen AJ;Fisher MT;Freudenthal BD
易位对炭疽毒素的机制至关重要。这种AB毒素的结合成分保护性抗原（PA）形成一个寡聚孔，将毒素的活性成分致死因子（LF）或水肿因子转运到细胞中。易位过程的结构细节尽管具有重要的生物学意义，但仍然难以捉摸。为了克服研究易位中间体的技术挑战，我们开发了一种固定、过渡和稳定炭疽毒素的方法来模拟中毒过程中的重要生理步骤。在这里，我们报道了一个低温电镜快照的PApore转移的n端结构域的LF （LFN）。得到的3.3 Å结构显示了在典型的PApore结合位点附近部分展开的LFN的密度。有趣的是，我们还观察到密度与从100 Å β桶通道中出现的α螺旋一致，这表明LF二级结构元素开始在孔隙通道中重新折叠。我们得出结论，炭疽毒素β桶有助于在通道出口之前有效折叠其酶负载。我们假设的重折叠机制对其他蛋白质转运毒素的孔隙长度具有更广泛的意义。
Translocation is essential to the anthrax toxin mechanism. Protective antigen (PA), the binding component of this AB toxin, forms an oligomeric pore that translocates lethal factor (LF) or edema factor, the active components of the toxin, into the cell. Structural details of the translocation process have remained elusive despite their biological importance. To overcome the technical challenges of studying translocation intermediates, we developed a method to immobilize, transition, and stabilize anthrax toxin to mimic important physiological steps in the intoxication process. Here, we report a cryoEM snapshot of PApore translocating the N-terminal domain of LF (LFN). The resulting 3.3 Å structure of the complex shows density of partially unfolded LFN near the canonical PApore binding site. Interestingly, we also observe density consistent with an α helix emerging from the 100 Å β barrel channel suggesting LF secondary structural elements begin to refold in the pore channel. We conclude the anthrax toxin β barrel aids in efficient folding of its enzymatic payload prior to channel exit. Our hypothesized refolding mechanism has broader implications for pore length of other protein translocating toxins.
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DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
3.4
作者：
Knapp, Oliver;Maier, Elke;Popoff, Michel R.
通讯作者：
Popoff, Michel R.
影响因子：
8
作者：
Akkaladevi, N.;Hinton-Chollet, L.;Fisher, M. T.
通讯作者：
Fisher, M. T.
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH
影响因子：
3.4
作者：
Dmochewitz L;Lillich M;Kaiser E;Jennings LD;Lang AE;Buchner J;Fischer G;Aktories K;Collier RJ;Barth H
通讯作者：
Barth H