Yamaguchi S, Aizawa S, Kihara M, Isomura M, Jones C J, Macnab R M
J Bacteriol. 1986 Dec;168(3):1172-9. doi: 10.1128/jb.168.3.1172-1179.1986.
The flaAII.2, flaQ, and flaN genes of Salmonella typhimurium are important for assembly, rotation, and counterclockwise-clockwise switching of the flagellar motor. Paralyzed and nonchemotactic mutants were subjected to selection pressure for partial acquisition of motility and chemotaxis, and the suppressor mutations of the resulting pseudorevertants were mapped and isolated. Many of the intergenic suppressor mutations were in one of the other two genes. Others were in genes for cytoplasmic components of the chemotaxis system, notably cheY and cheZ; one of the mutations was found in the cheA gene and one in a motility gene, motB. Suppression among the three fla genes was allele specific, and many of the pseudorevertants were either cold sensitive or heat sensitive. We conclude that the FlaAII.2, FlaQ, and FlaN proteins form a complex which determines the rotational sense, either counterclockwise or clockwise, of the motor and also participates in the conversion of proton energy into mechanical work of rotation. This switch complex is probably mounted to the base of the flagellar basal body and, via binding of the CheY and CheZ proteins, receives sensory information and uses it to control flagellar operation.
鼠伤寒沙门氏菌的flaAII.2、flaQ和flaN基因对于鞭毛马达的组装、旋转以及逆时针-顺时针转换至关重要。对瘫痪且无趋化性的突变体施加选择压力，以使其部分恢复运动性和趋化性，然后对所得假回复突变体的抑制突变进行定位和分离。许多基因间抑制突变存在于另外两个基因之一中。其他的则存在于趋化系统细胞质成分的基因中，特别是cheY和cheZ；其中一个突变存在于cheA基因中，另一个存在于运动基因motB中。三个fla基因之间的抑制是等位基因特异性的，许多假回复突变体要么对冷敏感，要么对热敏感。我们得出结论，FlaAII.2、FlaQ和FlaN蛋白形成一个复合体，该复合体决定马达的旋转方向（逆时针或顺时针），并且还参与将质子能量转化为旋转的机械功。这个开关复合体可能安装在鞭毛基体的基部，并通过CheY和CheZ蛋白的结合接收感官信息并利用它来控制鞭毛的运作。
