Subcellular organization of the Tat translocation machinery

双精氨酸易位（达特）机制可以跨生物膜转运折叠蛋白。达特系统的组成部分已经确定，其结构和功能是目前国际研究的主题。通过将绿色荧光蛋白（GFP）融合到来自大肠杆菌的达特组分，我们最近揭示了TatB和TatC（translocon的两个必需组分）主要极性定位在细胞内（Berthelmann和Brüser，2004）。相比之下，TatA分布不太集中在极点。我们现在计划研究的结构基础和功能的后果，这种亚细胞组织的translocon组件。将通过GFP融合技术和电子显微镜详细研究达特系统组分的不同组合的定位。正如我们所期望的初步结果，所观察到的极性结构可能有助于显着的理解达特系统的功能。电子显微镜分析将在邻近生物中心的显微镜单元中进行。已知的极性决定因素的作用-如最小系统或细菌蛋白的肌动蛋白家族-将得到解决。 将通过体内和体外蛋白质相互作用分析来分析分选因子，并将在体内测试其功能。

The twin-arginine translocation (Tat) machinery can translocate folded proteins across biological membranes. Components of the Tat system have been identified and their structure and function are subject of current international research. By fusing the green fluorescent protein (GFP) to the Tat components from Escherichia coli, we recently revealed that TatB and TatC, two essential components of the translocon, are mainly polarly localized within the cells (Berthelmann and Brüser, 2004). In contrast, TatA distribution is less focussed at the poles. We now plan to study the structural basis and functional consequences for this subcellular organization of the translocon components. The localization of different combinations of Tat system components will be studied in detail by GFP-fusion techniques and electron microscopy. As we expect from preliminary results, observed polar structures might contribute significantly to the understanding of Tat system functionality. The electron micros-copical analyses will be carried out in the microscopy unit at the neighbouring Biocenter. The role of known polarity determining factors - such as the Min system or bacterial proteins of the actin-family - will be addressed. Sorting factors will be analyzed by in vivo and in vitro protein interaction analyses and their functionality will be tested in vivo.