Determination of whole complex structure of decarboxylase sodium pump

草酰乙酸酯脱羧酶初级钠泵复合体(OAD)在厌氧条件下为某些病原菌的生存提供能量。OAD由三个亚基组成：OAD-α、OAD-β和OAD-γ。每个亚基都有特征，但OAD作为一个整体的机制仍不清楚。对整个OAD络合物的测定，不仅可以揭示能量偶联的分子机制，还可以揭示亚基的化学计量比。在结构分析的初始阶段，需要对稳定和高质量的蛋白质进行纯化。据报道，我们成功地提纯了高质量的OAD2复合体用于结构分析，并建议OAD亚基的化学计量比为4：2：2而不是1：1：1。

The oxaloacetate decarboxylase primary Na+ pump complex (OAD) functions in energy generation for the surviving of some pathogenic bacteria under anaerobic conditions. OAD composes of three subunits: OAD-alpha, OAD-beta and OAD-gamma. Each subunit is characterized but the mechanism of OAD as a whole complex remains still unclear. The determination of the whole complex of OAD is expected to reveal not only the molecular mechanism of the energetic coupling but also the stoichiometry of subunits. At the initial stage of structural analysis, a purification of stable and high quality proteins is required. Here it is reported that we succeeded in purification of high quality Oad2 complex for structural analysis and it is suggested that the stoichiometry of OAD subunits is 4:2:2 instead of 1:1:1.