Effect of rfaH (sfrB) and temperature on expression of rfa genes of Escherichia coli K-12.
Effect of rfaH (sfrB) and temperature on expression of rfa genes of Escherichia coli K-12.
复制标题
rfaH (sfrB) 和温度对大肠杆菌 K-12 rfa 基因表达的影响。
DOI：
10.1128/jb.173.20.6428-6431.1991
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发表时间：
1991
影响因子：
3.2
通讯作者：
Schnaitman,CA
中科院分区：
文献类型：
--
作者：
Pradel,E;Schnaitman,CA
为了研究大肠杆菌K-12中参与脂多糖核心合成和修饰的RFA基因大片段的调控，利用转座子TnlacZ产生了与该片段中5个基因(rfaQ、-G、-P、-B和-J)编码区的框内LacZ融合。当rfaH11(SfrB11)等位基因被引入时，这些融合进入染色体RFA基因座的菌株的β-半乳糖苷酶活性显著降低，当这些菌株用携带野生型rfaH的Lambda噬菌体裂解时，这些菌株的β-半乳糖苷酶活性恢复到野生型水平。这表明rfaH编码的正调控功能在整个基因块中都是必需的。此外，在42℃下生长，LacZ融合到rfaJ的表达减少，这与温度诱导的核心脂多糖的电泳谱的变化有关。
In order to study the regulation of a large block of contiguous genes at the rfa locus of Escherichia coli K-12 which are involved in synthesis and modification of the lipopolysaccharide core, the transposon TnlacZ was used to generate in-frame lacZ fusions to the coding regions of five genes (rfaQ, -G, -P, -B and -J) within this block. The beta-galactosidase activity of strains in which these fusions had been crossed into the chromosomal rfa locus was significantly decreased when the rfaH11 (sfrB11) allele was introduced and was restored to wild-type levels when these strains were lysogenized with a lambda phage carrying wild-type rfaH. This indicates that the positive regulatory function encoded by rfaH is required throughout this block of genes. In addition, expression of the lacZ fusion to rfaJ was reduced by growth at 42 degrees C, and this correlated with a temperature-induced change in the electrophoretic profile of the core lipopolysaccharide.