Zuberi A R, Ying C W, Parker H M, Ordal G W
Department of Biochemistry, College of Medicine, University of Illinois, Urbana 61801.
J Bacteriol. 1990 Dec;172(12):6841-8. doi: 10.1128/jb.172.12.6841-6848.1990.
We have used Tn917lacZ to mutagenize the Bacillus subtilis chromosome and have isolated mutants that are defective in chemotaxis and motility. Mapping of the transposon inserts identified two new loci. Mutations in one of these loci generated mutants that had paralyzed flagella. Accordingly, we designate this a mot locus. The other locus is closely linked to the first and encodes proteins specifying chemotaxis functions. This locus is designated the cheX locus. Both the mot and cheX loci map close to ptsI. An additional transposon insert that maps in the hag locus was obtained. The pattern of beta-galactosidase expression from some of the transposons suggested that the mot locus is regulated by sigD, a minor sigma factor of B. subtilis. The cheX locus appeared to be under the control of vegetative sigA. Four transposon inserts were mapped to a previously characterized che locus near spcB. These mutants did not produce flagellin and were defective in the methylation of the methyl-accepting chemotaxis proteins. This locus probably encodes proteins required for flagellum biosynthesis and other proteins that are required for the methylation response.
我们利用Tn917lacZ对枯草芽孢杆菌染色体进行诱变，分离出了趋化性和运动性存在缺陷的突变体。转座子插入位点的定位确定了两个新位点。其中一个位点发生突变产生的突变体鞭毛麻痹。因此，我们将此位点命名为mot位点。另一个位点与第一个位点紧密连锁，编码指定趋化功能的蛋白质。该位点被命名为cheX位点。mot和cheX位点均定位于ptsI附近。获得了一个定位在hag位点的额外转座子插入。一些转座子的β-半乳糖苷酶表达模式表明，mot位点受枯草芽孢杆菌的一个次要σ因子sigD调控。cheX位点似乎受营养型sigA的控制。四个转座子插入被定位到spcB附近一个先前已鉴定的che位点。这些突变体不产生鞭毛蛋白，甲基接受趋化蛋白的甲基化存在缺陷。该位点可能编码鞭毛生物合成所需的蛋白质以及甲基化反应所需的其他蛋白质。
