From the Institut de Biologie Structurale, University of Grenoble Alpes-CEA, CNRS, IBS, 71 Avenue des Martyrs, CS 10090, 38044 Grenoble Cedex 9, France.
the European Molecular Biology Laboratory, 71 avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France.
J Biol Chem. 2018 Jun 1;293(22):8379-8393. doi: 10.1074/jbc.RA118.002251. Epub 2018 Apr 9.
can remain dormant in the host, an ability that explains the failure of many current tuberculosis treatments. Recently, the natural products cyclomarin, ecumicin, and lassomycin have been shown to efficiently kill persisters. Their target is the N-terminal domain of the hexameric AAA+ ATPase ClpC1, which recognizes, unfolds, and translocates protein substrates, such as proteins containing phosphorylated arginine residues, to the ClpP1P2 protease for degradation. Surprisingly, these antibiotics do not inhibit ClpC1 ATPase activity, and how they cause cell death is still unclear. Here, using NMR and small-angle X-ray scattering, we demonstrate that arginine-phosphate binding to the ClpC1 N-terminal domain induces millisecond dynamics. We show that these dynamics are caused by conformational changes and do not result from unfolding or oligomerization of this domain. Cyclomarin binding to this domain specifically blocked these N-terminal dynamics. On the basis of these results, we propose a mechanism of action involving cyclomarin-induced restriction of ClpC1 dynamics, which modulates the chaperone enzymatic activity leading eventually to cell death.
可以在宿主体内潜伏，这种能力解释了许多当前结核病治疗方法失败的原因。最近，天然产物环马琳、依古霉素和拉索霉素已被证明能有效地杀死休眠细胞。它们的作用靶点是六聚体 AAA+ ATP 酶 ClpC1 的 N 端结构域，该结构域识别、展开并转运蛋白底物，如含有磷酸化精氨酸残基的蛋白，到 ClpP1P2 蛋白酶进行降解。令人惊讶的是，这些抗生素并不抑制 ClpC1 ATP 酶的活性，它们如何导致细胞死亡仍不清楚。在这里，我们使用 NMR 和小角 X 射线散射证明了 ClpC1 N 端结构域与精氨酸-磷酸结合诱导毫秒级动力学。我们表明，这些动力学是由构象变化引起的，而不是该结构域的展开或寡聚化引起的。环马琳与该结构域的结合特异性地阻断了这些 N 端动力学。基于这些结果，我们提出了一种作用机制，涉及环马琳诱导的 ClpC1 动力学受限，从而调节伴侣酶的酶活性，最终导致细胞死亡。
