Nolandt Olga V, Walther Torsten H, Roth Siegmar, Bürck Jochen, Ulrich Anne S
Karlsruhe Institute of Technology, Institut für Biologische Grenzflächen , Forschungszentrum Karlsruhe, D-76021 Karlsruhe, Germany.
Biochim Biophys Acta. 2009 Oct;1788(10):2238-44. doi: 10.1016/j.bbamem.2009.07.003. Epub 2009 Jul 16.
The twin arginine translocation (Tat) system can transport fully folded proteins, including their cofactors, across bacterial and thylakoid membranes. The Tat system of Bacillus subtilis that serves to export the phosphodiesterase (PhoD) consists of only two membrane proteins, TatA(d) and TatC(d). The larger component TatC(d) has a molecular weight of 28 kDa and several membrane-spanning segments. This protein has been expressed in Escherichia coli and purified in sufficient amounts for structure analysis by circular dichroism (CD) and NMR spectroscopy. TatC(d) was reconstituted in detergent micelles and in lipid bilayers for CD analysis in solution and in macroscopically oriented samples, to examine the stability of the protein. Suitable protocols and model membrane systems have been established, by which TatC(d) maintains the level of helicity close to theoretically predicted, and its transmembrane alignment could been verified.
双精氨酸转运（Tat）系统能够将包括辅因子在内的完全折叠的蛋白质转运穿过细菌膜和类囊体膜。枯草芽孢杆菌用于输出磷酸二酯酶（PhoD）的Tat系统仅由两种膜蛋白TatA(d)和TatC(d)组成。较大的组分TatC(d)分子量为28 kDa，有几个跨膜片段。该蛋白已在大肠杆菌中表达，并纯化出足够的量用于通过圆二色性（CD）和核磁共振（NMR）光谱进行结构分析。TatC(d)被重构到去污剂胶束和脂质双层中，用于溶液和宏观取向样品的CD分析，以检测该蛋白的稳定性。已经建立了合适的方案和模型膜系统，通过这些，TatC(d)保持的螺旋水平接近理论预测值，并且其跨膜排列得以验证。
