Marykwas D L, Schmidt S A, Berg H C
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
J Mol Biol. 1996 Mar 1;256(3):564-76. doi: 10.1006/jmbi.1996.0109.
The ability of the flagellar motor of Escherichia coli to switch between clockwise and counterclockwise modes of operation is ultimately responsible for the swimming behavior of the cell. Three motor proteins, FliG, FliM, and FliN, have been implicated in this process. Using the two-hybrid system in Saccharomyces cerevisiae, we demonstrated strong interactions between FliG/FliM,FliM/FliM, and FliM/FliN. A screen for other components that might interact with FliG revealed interactions with FliF (the MS ring protein) and H-NS (a histone-like protein). Regions of proteins important for several of these interactions were identified by mutational analysis. The implications for motor assembly and function are discussed.
大肠杆菌鞭毛马达在顺时针和逆时针运转模式之间切换的能力最终决定了细胞的游动行为。三种马达蛋白，即FliG、FliM和FliN，参与了这一过程。利用酿酒酵母中的双杂交系统，我们证明了FliG/FliM、FliM/FliM和FliM/FliN之间存在强烈的相互作用。对可能与FliG相互作用的其他组分进行的筛选揭示了其与FliF（膜周质环蛋白）和H-NS（一种类组蛋白）之间的相互作用。通过突变分析确定了对其中几种相互作用至关重要的蛋白质区域。文中讨论了这些发现对马达组装和功能的意义。
