Müller Matthias, Klösgen Ralf Bernd
Institute of Biochemistry and Molecular Biology, University of Freiburg, Freiburg, Germany.
Mol Membr Biol. 2005 Jan-Apr;22(1-2):113-21. doi: 10.1080/09687860500041809.
Both in prokaryotic organisms and in chloroplasts, a specialized protein transport pathway exists which is capable of translocating proteins in a fully folded conformation. Transport is mediated in both instances by signal peptides harbouring a twin-arginine consensus motif (twin-arginine translocation (Tat) pathway). The Tat translocase comprises the three functionally different membrane proteins TatA, TatB, and TatC. While TatB and TatC are involved in the specific recognition of the substrate, TatA might be the major pore-forming component. Current evidence suggests that a functional Tat translocase is assembled from separate TatBC and TatA assemblies only on demand, i.e., in the presence of transport substrate and a transmembrane H+-motive force.
在原核生物和叶绿体中，都存在一种特殊的蛋白质转运途径，它能够转运完全折叠构象的蛋白质。在这两种情况下，转运都是由带有双精氨酸共有基序的信号肽介导的（双精氨酸转运（Tat）途径）。Tat转位酶由三种功能不同的膜蛋白TatA、TatB和TatC组成。虽然TatB和TatC参与底物的特异性识别，但TatA可能是主要的成孔成分。目前的证据表明，功能性的Tat转位酶仅在需要时，即在存在转运底物和跨膜H⁺动力势的情况下，由单独的TatBC和TatA组装体组装而成。
