Contribution of the fnr and arcA gene products in coordinate regulation of cytochrome o and d oxidase (cyoABCDE and cydAB) genes in Escherichia coli.
Contribution of the fnr and arcA gene products in coordinate regulation of cytochrome o and d oxidase (cyoABCDE and cydAB) genes in Escherichia coli.
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DOI：
10.1016/0378-1097(92)90558-6
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发表时间：
1992-02
影响因子：
2.1
通讯作者：
Peggy A. Cotter;R. Gunsalus
中科院分区：
文献类型：
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作者：
Peggy A. Cotter;R. Gunsalus
用lacZ报告基因与cydAB操纵子和cycoABCDE的融合，研究了fnrandarcA调节基因产物对大肠杆菌细胞色素o氧化酶和细胞色素d氧化酶基因表达的单独和联合作用。Fnr在厌氧生长过程中抑制cyolac和cyd-lacZ的表达，但在好氧生长条件下不抑制。ArcA作为cyo-lacZ表达的厌氧阻遏物发挥作用，而相反，它在有氧和厌氧生长期间激活cydAB表达。ArcA和Fnr似乎彼此独立地起作用以控制cycoABCDE操纵子表达。相反，FNR对cydAB表达的抑制依赖于arcA+，如在anarcA菌株中nr+质粒不能抑制cydAB-lacZ表达所示。在任何试验条件下，Fnr都不能激活AB的表达。大多数，但不是全部，所观察到的有氧/厌氧调节cyo和cyd是由两个转录调节。这些数据表明，存在额外的厌氧基因控制在E。杆菌此外，发现非调节基因的表达和厌氧呼吸基因narGHJI、dmsAB和dABCD的调节不依赖于ArcA。
The individual and the combined effect of thefnrandarcAregulatory gene products on cytochrome o oxidase and cytochrome d oxidase gene expression inEscherichia coliwere evaluated usinglacZreporter fusions to thecyoABCDEandcydABoperons. Fnr repressedcyolacZandcyd-lacZexpression during anaerobic growth but not during aerobic growth conditions. ArcA functioned as an anaerobic repressor ofcyo-lacZexpression while, in contrast, it activatedcydABexpression during both aerobic and anaerobic growth. ArcA and Fnr appear to function independently of each other to controlcyoABCDEoperon expression. In contrast, FNR repression ofcydABexpression was dependent onarcA+, as indicated by the inability offnr+plasmids to represscyd-lacZexpression in anarcAstrain. Under no conditions tested did Fnr activatecydABexpression. Most, but not all, of the observed aerobic/anaerobic regulation ofcyoandcydwas accounted for by the two transcriptional regulators. These data suggest the existence of additional levels of anaerobic gene control inE. coli. Additionally, the expression of thefnrregulatory gene, and regulation of the anaerobic respiratory genes,narGHJI, dmsABCandfrdABCD, was found to be independent of ArcA.