Vonderviszt Ferenc, Sajó Ráchel, Dobó József, Závodszky Péter
Research Institute of Chemical and Process Engineering, Faculty of Information Technology, University of Pannonia, Veszprém, Hungary.
Methods Mol Biol. 2012;824:131-43. doi: 10.1007/978-1-61779-433-9_6.
The flagellum-specific export system is a specialized type III export machinery, which exports external flagellar proteins through the central channel of the flagellar filament. A number of evidence indicates that short segments within the disordered N-terminal region of flagellar axial proteins are recognized by the flagellum-specific export apparatus. Recently, we have demonstrated that the 26-47 segment of Salmonella typhimurium flagellin is capable of mediating flagellar export. N-terminal flagellin segments containing the export signal combined with a hexahistidine tag can be attached to heterologous proteins (preferentially in the size range of 9-40 kDa) facilitating their secreted expression and easy purification from the medium. Certain over-expressed proteins that are easily degraded within the cells are found intact in the medium implying a potential application of this expression system for proteins of high proteolytic susceptibility.
鞭毛特异性输出系统是一种特殊的III型输出机制，它通过鞭毛丝的中央通道输出外部鞭毛蛋白。大量证据表明，鞭毛轴蛋白无序N端区域内的短片段可被鞭毛特异性输出装置识别。最近，我们证明了鼠伤寒沙门氏菌鞭毛蛋白的26 - 47片段能够介导鞭毛输出。含有输出信号并与六组氨酸标签结合的N端鞭毛蛋白片段可连接到异源蛋白上（优先选择9 - 40 kDa大小范围的蛋白），促进其分泌表达并便于从培养基中纯化。某些在细胞内易降解的过表达蛋白在培养基中保持完整，这意味着该表达系统在高蛋白酶敏感性蛋白方面具有潜在应用价值。
