Berks Ben C, Lea Susan M, Stansfeld Phillip J
Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, United Kingdom.
Curr Opin Struct Biol. 2014 Aug;27:32-7. doi: 10.1016/j.sbi.2014.03.003. Epub 2014 Apr 5.
The Tat protein transport system is found in the cytoplasmic membrane of prokaryotes and the thylakoid membrane of plant chloroplasts. Unusually, the Tat system translocates proteins only after they have folded. Proteins are targeted to the Tat system by specific N-terminal signal peptides. High resolution structures have recently been determined for the TatA and TatC proteins that form the Tat translocation site. These structures provide a molecular framework for understanding the mechanism of Tat transport. The interactions between TatC and the signal peptide of the substrate protein can be provisionally modelled. However, the way that TatA and TatC combine in the active translocation site remains to be definitively established.
Tat蛋白转运系统存在于原核生物的细胞质膜和植物叶绿体的类囊体膜中。不同寻常的是，Tat系统仅在蛋白质折叠后才转运它们。蛋白质通过特定的N端信号肽靶向Tat系统。最近已确定了形成Tat转运位点的TatA和TatC蛋白的高分辨率结构。这些结构为理解Tat转运机制提供了分子框架。TatC与底物蛋白信号肽之间的相互作用可以初步建模。然而，TatA和TatC在活性转运位点的结合方式仍有待最终确定。
