Role of multiple ArcA recognition sites in anaerobic regulation of succinate dehydrogenase (sdhCDAB) gene expression in Escherichia coli.
Role of multiple ArcA recognition sites in anaerobic regulation of succinate dehydrogenase (sdhCDAB) gene expression in Escherichia coli.
复制标题
多个 ArcA 识别位点在大肠杆菌琥珀酸脱氢酶 (sdhCDAB) 基因表达厌氧调节中的作用。
DOI：
10.1046/j.1365-2958.1997.5561923.x
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发表时间：
1997
影响因子：
3.6
通讯作者：
Gunsalus,RP
中科院分区：
文献类型：
--
作者：
Shen,J;Gunsalus,RP
Succinate dehydrogenase (sdhCDAB) gene expression inEscherichia coliis negatively regulated by thearcAandfnrgene products during anaerobic cell growth conditions. The controlled synthesis of this sole membrane‐bound enzyme of the tricarboxylic acid cycle allows optimal participation in the aerobic electron transport pathway for the generation of energy via oxidative phosphorylation reactions. To understand how ArcA participates in the anaerobic repression ofsdhCDABexpression, a family ofsdhC–lacZfusions was constructed and analysedin vivo. DNase I footprint and gel shift assays using purified ArcA protein revealed the location of four distinct and independent ArcA binding sites in thesdhCpromoter region. ArcA sites, designated sites 1 and 2, are centred at −205 bp and −119 bp upstream of thesdhCpromoter, respectively, whereas ArcA site 3 overlaps the −35 and −10 regions of thesdhCpromoter. A fourth ArcA site is centred at + 257 bp downstream of thesdhCpromoter. They are bound with differing affinity by ArcA and ArcA phosphate. Thein vivostudies, in combination with thein vitrostudies, indicate that ArcA site 3 is necessary and sufficient for the ArcA‐dependent repression ofsdhCgene expression, while the DNA region containing ArcA site 2 contributes to maximal gene expression. The DNA‐containing ArcA sites 1 and 4 provide minor roles in the ArcA regulation ofsdhCexpression. Lastly, the Fnr‐dependent control ofsdhCDABgene expression was shown to occur independently of the ArcA and to require DNA sequences near the start ofsdhCtranscription.
