Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan.
Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan.
Nat Commun. 2016 Oct 27;7:13235. doi: 10.1038/ncomms13235.
V-ATPases are highly conserved ATP-driven rotary molecular motors found in various membrane systems. We recently reported the crystal structures for the Enterococcus hirae ABDF (V) complex, corresponding to the catalytic dwell state waiting for ATP hydrolysis. Here we present the crystal structures for two other dwell states obtained by soaking nucleotide-free V crystals in ADP. In the presence of 20 μM ADP, two ADP molecules bind to two of three binding sites and cooperatively induce conformational changes of the third site to an ATP-binding mode, corresponding to the ATP-binding dwell. In the presence of 2 mM ADP, all nucleotide-binding sites are occupied by ADP to induce conformational changes corresponding to the ADP-release dwell. Based on these and previous findings, we propose a V-ATPase rotational mechanism model.
V-ATPases 是高度保守的 ATP 驱动的旋转分子马达，存在于各种膜系统中。我们最近报道了肠球菌 ABDF（V）复合物的晶体结构，该结构对应于等待 ATP 水解的催化停留状态。在这里，我们展示了通过在无核苷酸 V 晶体中浸泡 ADP 获得的另外两种停留状态的晶体结构。在 20μM ADP 的存在下，两个 ADP 分子结合到三个结合位点中的两个，协同诱导第三个位点的构象变化为 ATP 结合模式，对应于 ATP 结合停留。在 2mM ADP 的存在下，所有核苷酸结合位点都被 ADP 占据，以诱导与 ADP 释放停留相对应的构象变化。基于这些和以前的发现，我们提出了 V-ATPase 旋转机制模型。
