Co-regulation of lipoamide dehydrogenase and 2-oxoglutarate dehydrogenase synthesis in Escherichia coli:: characterisation of an ArcA binding site in the lpd promoter
Co-regulation of lipoamide dehydrogenase and 2-oxoglutarate dehydrogenase synthesis in Escherichia coli:: characterisation of an ArcA binding site in the lpd promoter
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DOI：
10.1016/s0378-1097(98)00506-0
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发表时间：
1998-12-15
影响因子：
2.1
通讯作者：
Guest, JR
中科院分区：
文献类型：
--
作者：
Cunningham, L;Georgellis, D;Guest, JR
硫酰胺脱氢酶基因(LpdA)编码大肠杆菌丙酮酸脱氢酶和2-氧戊二酸脱氢酶复合体的E3亚基，由PDH操纵子的上游PDH和内部LPD启动子(pdhR-aceEF-lpdA)表达。在有氧条件下，sdhCDAB-ucABCD操纵子中的suAB基因编码的2-氧戊二酸脱氢酶复合体的特定成分来自SDH启动子。因此，可以通过LPD启动子和SDH启动子的共同调节来控制用于组装成2-氧戊二酸脱氢酶复合体的硫酰胺脱氢酶亚单位的提供。在此，通过引物延伸分析确定了LPD启动子的转录起始点，通过体外足迹分析确定了与LPD启动子重叠的Arca结合位点TGTTAACAAT，并在10个位置中有8个与共识一致。PdhR不与LPD启动子结合，也不与PDH启动子特异结合。这些结果支持这样的观点，即LPD和SDH启动子的共同调节主要是由Arca介导的。(C)1998年欧洲微生物学会联合会。爱思唯尔科学公司出版。版权所有。
The lipoamide dehydrogenase gene (lpdA) encoding the E3 subunits of both the pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase complexes of Escherichia coli, is expressed from the upstream pdh and internal lpd promoters of the pdh operon (pdhR-aceEF-lpdA). Under aerobic conditions, the specific components of the 2-oxoglutarate dehydrogenase complex encoded by the sucAB genes in the sdhCDAB-sucABCD operon are expressed from the sdh promoter. The provision of lipoamide dehydrogenase subunits for assembly into the 2-oxoglutarate dehydrogenase complex could thus be controlled by co-regulation of the lpd promoter with the sdh promoter. Here, the transcription start point of the lpd promoter was defined by primer extension analysis, and an ArcA binding site, TGTTAACAAT, overlapping the lpd promoter and matching the consensus at 8 out of 10 positions, was identified by in vitro footprint analysis. PdhR was not bound to the lpd promoter nor was ArcA bound specifically to the pdh promoter. These results support the view that co-regulation of the lpd and sdh promoters is mediated primarily by ArcA. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.