Kipping Marc, Lilie Hauke, Lindenstrauss Ute, Andreesen Jan R, Griesinger Christian, Carlomagno Teresa, Brüser Thomas
Max Planck Research Unit for Enzymology of Protein Folding, Weinbergweg 22, D-06120 Halle, Germany.
FEBS Lett. 2003 Aug 28;550(1-3):18-22. doi: 10.1016/s0014-5793(03)00804-4.
Translocation of folded proteins across biological membranes can be mediated by the so-called 'twin-arginine translocation' (Tat) system. To be translocated, Tat substrates require N-terminal signal sequences which usually contain the eponymous twin-arginine motif. Here we report the first structural analysis of a twin-arginine signal sequence, the signal sequence of the high potential iron-sulfur protein from Allochromatium vinosum. Nuclear magnetic resonance (NMR) analyses of amide proton resonances did not indicate a signal sequence structure. Accordingly, data from H/D exchange matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry showed that the amide protons of the signal sequence exchange rapidly, indicating the absence of secondary structure in the signal sequence up to L29. We conclude that the conserved twin-arginine motif does not form a structure by itself or as a result of intramolecular interactions.
折叠蛋白跨生物膜的转运可由所谓的“双精氨酸转运”（Tat）系统介导。为了实现转运，Tat底物需要N端信号序列，该序列通常包含同名的双精氨酸基序。本文我们报道了首个双精氨酸信号序列的结构分析，该信号序列来自嗜酒色杆菌的高电位铁硫蛋白。酰胺质子共振的核磁共振（NMR）分析未表明信号序列结构。因此，氢/氘交换基质辅助激光解吸/电离飞行时间（MALDI-TOF）质谱数据显示，信号序列的酰胺质子快速交换，表明直至L29信号序列中不存在二级结构。我们得出结论，保守的双精氨酸基序自身不会形成结构，也不会因分子内相互作用而形成结构。
