Rusch Sharyn L, Kendall Debra A
Department of Molecular and Cell Biology, The University of Connecticut, Storrs, Connecticut 06269-3125, USA.
Biochemistry. 2007 Aug 28;46(34):9665-73. doi: 10.1021/bi7010064. Epub 2007 Aug 3.
Understanding the transport of hydrophilic proteins across biological membranes continues to be an important undertaking. The general secretory (Sec) pathway in Escherichia coli transports the majority of E. coli proteins from their point of synthesis in the cytoplasm to their sites of final localization, associating sequentially with a number of protein components of the transport machinery. The targeting signals for these substrates must be discriminated from those of proteins transported via other pathways. While targeting signals for each route have common overall characteristics, individual signal peptides vary greatly in their amino acid sequences. How do these diverse signals interact specifically with the proteins that comprise the appropriate transport machinery and, at the same time, avoid targeting to an alternate route? The recent publication of the crystal structures of components of the Sec transport machinery now allows a more thorough consideration of the interactions of signal sequences with these components.
了解亲水性蛋白质跨生物膜的运输仍然是一项重要工作。大肠杆菌中的一般分泌（Sec）途径将大多数将大多数大肠杆菌蛋白质从其在细胞质中的合成点运输到其最终定位位点，依次与运输机制的许多蛋白质成分相关联。必须将这些底物的靶向信号与通过其他途径运输的蛋白质的靶向信号区分开来。虽然每条途径的靶向信号具有共同的总体特征，但各个信号肽的氨基酸序列差异很大。这些不同的信号如何与构成适当运输机制的蛋白质特异性相互作用，同时避免靶向其他途径？Sec运输机制组件晶体结构的最新发表现在允许更全面地考虑信号序列与这些组件的相互作用。
