IDENTIFICATION, CLONING, AND CHARACTERIZATION OF RCSF, A NEW REGULATOR GENE FOR EXOPOLYSACCHARIDE SYNTHESIS THAT SUPPRESSES THE DIVISION MUTATION FTSZ84 IN ESCHERICHIA-COLI K-12
IDENTIFICATION, CLONING, AND CHARACTERIZATION OF RCSF, A NEW REGULATOR GENE FOR EXOPOLYSACCHARIDE SYNTHESIS THAT SUPPRESSES THE DIVISION MUTATION FTSZ84 IN ESCHERICHIA-COLI K-12
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DOI：
10.1128/jb.174.24.8016-8022.1992
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发表时间：
1992-12-01
影响因子：
3.2
通讯作者：
DRAPEAU, GR
中科院分区：
文献类型：
--
作者：
GERVAIS, FG;DRAPEAU, GR
一个新的基因，命名为rcsF，位于大肠杆菌的遗传图谱的5.2分钟的位置附近的drpA。由rcsF基因编码的推导的氨基酸序列指示具有10.8的计算pI的133个氨基酸残基的小蛋白质，其富含脯氨酸、丝氨酸、丙氨酸和半胱氨酸残基。当由于其存在于多拷贝质粒上而过表达时，rcsF赋予粘液样表型并在不含添加NaCl的L琼脂培养基上恢复ftsZ84突变细胞的集落形成。在rcsB突变细胞中未观察到这两种表型。携带rcsF突变的lon突变体细胞积累的胞外多糖水平相当低，而多拷贝rcsF质粒的存在不仅增加了荚膜合成，而且在37 ℃下赋予粘液样表型，已知lon突变体细胞在该温度下不形成粘液样集落。RcsF不刺激rcsB的表达，表明它通过RcsB蛋白发挥作用，可能是通过磷酸化。它还表明，RcsF刺激胶囊合成是RcsA依赖性的，而ftsZ84突变细胞的集落形成可以恢复RcsF在RcsA的情况下。
A new gene, designated rcsF, was located adjacent to drpA at the 5.2-min position of the genetic map of Escherichia coli. The deduced amino acid sequence encoded by the rcsF gene indicates a small protein of 133 amino acid residues with a calculated pI of 10.8 that is rich in proline, serine, alanine, and cysteine residues. When overexpressed as a result of its presence on a multicopy plasmid, rcsF confers a mucoid phenotype and restores colony formation to ftsZ84 mutant cells on L agar medium containing no added NaCl. These two phenotypes are not observed in rcsB mutant cells. lon mutant cells harboring an rcsF mutation accumulate considerably lower levels of exopolysaccharides, whereas the presence of a multicopy rcsF plasmid not only increases capsule synthesis but also confers a mucoid phenotype at 37-degrees-C, a temperature at which lon mutant cells are known not to form mucoid colonies. RcsF does not stimulate the expression of rcsB, indicating that it exerts its action through the RcsB protein, possibly by phosphorylation. It is also shown that RcsF stimulation of capsule synthesis is RcsA-dependent, whereas colony formation of ftsZ84 mutant cells can be restored by RcsF in the absence of RcsA.