Osbourn A E, Clarke B R, Stevens B J, Daniels M J
Sainsbury Laboratory, John Innes Institute, Norwich, UK.
Mol Gen Genet. 1990 Jun;222(1):145-51. doi: 10.1007/BF00283036.
Two-component regulatory systems comprising a sensor and a regulator protein, both with highly conserved amino acid domains, and commonly genetically linked, have been described in a range of bacterial species and are involved in sensing environmental stimuli. We used two oligonucleotide probes matching the postulated coding regions for domains of sensor and regulator proteins respectively in Xanthomonas campestris pathovar campestris (Xcc) to identify possible two-component regulatory systems in Xcc. Two different fragments of Xcc DNA with homology to both of these probes were cloned. The DNA sequence of part of one of these fragments encompassed a potential open reading frame (ORF), the predicted amino acid sequence of which had extensive homology with regulator proteins of two-component regulatory systems. Analysis of the predicted amino acid sequence for the 3' end of an adjacent ORF revealed a very high level of homology with the C-terminal end of sensor proteins. Strains of Xcc with Tn5-induced mutations in the regulator gene were affected in extracellular polysaccharide production, and also in resistance to salt and chloramphenicol. No effects of mutation in the second clone were observed.
由一个传感蛋白和一个调节蛋白组成的双组分调节系统，两者都具有高度保守的氨基酸结构域，且通常在基因上是连锁的，已在一系列细菌物种中被描述，并参与感知环境刺激。我们使用了两种寡核苷酸探针，分别与野油菜黄单胞菌野油菜致病变种（Xcc）中传感蛋白和调节蛋白结构域的假定编码区匹配，以鉴定Xcc中可能的双组分调节系统。克隆了与这两种探针均具有同源性的Xcc DNA的两个不同片段。其中一个片段的部分DNA序列包含一个潜在的开放阅读框（ORF），其预测的氨基酸序列与双组分调节系统的调节蛋白具有广泛的同源性。对相邻ORF 3'端预测氨基酸序列的分析显示，与传感蛋白的C末端具有非常高的同源性。在调节基因中具有Tn5诱导突变的Xcc菌株在胞外多糖产生以及对盐和氯霉素的抗性方面受到影响。未观察到第二个克隆中的突变有任何影响。
