Nuijten P J, Bleumink-Pluym N M, Gaastra W, van der Zeijst B A
Department of Bacteriology, School of Veterinary Medicine, University of Utrecht, The Netherlands.
Infect Immun. 1989 Apr;57(4):1084-8. doi: 10.1128/iai.57.4.1084-1088.1989.
Campylobacter jejuni 81116 is able to switch flagellum formation on and off. To study the expression of flagellin, the main component of flagella, an expression library of C. jejuni DNA was constructed in lambda gt11. Screening of this library with a flagellin-specific antiserum resulted in a clone producing a beta-galactosidase-flagellin fusion protein; it contained a DNA insert of 850 base pairs and coded for about 15 kilodaltons of the flagellin, corresponding to 410 base pairs of the flagellin gene. To study the regulation of the on-and-off switch of flagellum production, a nonmotile variant was isolated from semisolid medium. Western blots (immunoblots) showed the absence of flagellin in the nonmotile form. Southern blots of digested DNA of both motile, flagellate bacteria and nonmotile, aflagellate bacteria were identical, while Northern (RNA) blot analysis showed the absence of flagellin mRNA in the aflagellate form. Thus, it is concluded that reversible flagellin expression is regulated at the transcriptional level. Southern blots suggest that more than one flagellin gene is present. The structure and function of campylobacter flagellin can now be further investigated at the DNA level.
空肠弯曲菌81116能够开启和关闭鞭毛的形成。为了研究鞭毛的主要成分鞭毛蛋白的表达，构建了一个空肠弯曲菌DNA在λgt11中的表达文库。用鞭毛蛋白特异性抗血清筛选该文库，得到一个产生β-半乳糖苷酶-鞭毛蛋白融合蛋白的克隆；它含有一个850个碱基对的DNA插入片段，编码约15千道尔顿的鞭毛蛋白，对应于鞭毛蛋白基因的410个碱基对。为了研究鞭毛产生开关的调控，从半固体培养基中分离出一个无运动能力的变体。蛋白质免疫印迹法（免疫印迹）显示无运动能力的形式中不存在鞭毛蛋白。对有运动能力的鞭毛菌和无运动能力的无鞭毛菌的消化DNA进行的Southern印迹分析结果相同，而Northern（RNA）印迹分析显示无鞭毛菌形式中不存在鞭毛蛋白mRNA。因此，可以得出结论，鞭毛蛋白的可逆表达是在转录水平上调控的。Southern印迹表明存在不止一个鞭毛蛋白基因。现在可以在DNA水平上进一步研究弯曲菌鞭毛蛋白的结构和功能。
