Composition of the central stalk of the Na+‐pumping V‐ATPase from Caloramator fervidus
Composition of the central stalk of the Na+‐pumping V‐ATPase from Caloramator fervidus
复制标题
Caloramator fervidus 的 Na+ 泵 V-ATP 酶中央柄的组成
作者：
Y. Chaban;T. Ubbink‐Kok;W. Keegstra;J. Lolkema;E. Boekema
在控制条件下，纯化并分离了嗜热细菌卡乐马fervidus的Na+泵送V - atp酶复合体。通过电子显微镜和5万个投影的单颗粒分析，分析了不同亚基组成的纯化V1‐atp酶亚复合物的结构。亚复合体投影的差异映射揭示了两个亚基在中央茎上的存在和位置。与F - atp酶的γ亚基相似的细长形状的密度部分位于V1内，很可能与亚基E相对应。亚基E通过亚基C连接到膜结合部分V0，亚基C是连接到V0中心的球形密度。与γ亚基直接连接到F0的F‐atp酶相比，亚基C的存在使中心茎长得多。
The Na+‐pumping V‐ATPase complex of the thermophilic bacterium Caloramator fervidus was purified and dissociated under controlled conditions. The structure of purified V1‐ATPase subcomplexes differing in subunit composition was analyzed by electron microscopy and single particle analysis of 50 000 projections. Difference mapping of subcomplex projections revealed the presence and position of two subunits in the central stalk. A density with an elongated shape similar to the γ subunit of F‐ATPases is partly located within V1 and corresponds, most likely, to subunit E. Subunit E is connected to the membrane‐bound part V0 via subunit C, a spherical density that is connected to the center of V0. The presence of subunit C makes the central stalk substantially longer in comparison to the F‐ATPases, in which the γ subunit connects directly to F0.