Impact of global transcriptional regulation by ArcA, ArcB, Cra, Crp, Cya, Fnr, and Mlc on glucose catabolism in Escherichia coli
Impact of global transcriptional regulation by ArcA, ArcB, Cra, Crp, Cya, Fnr, and Mlc on glucose catabolism in Escherichia coli
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DOI：
10.1128/jb.187.9.3171-3179.2005
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发表时间：
2005-05-01
影响因子：
3.2
通讯作者：
Sauer, U
中科院分区：
文献类型：
--
作者：
Perrenoud, A;Sauer, U
尽管转录调控在建立代谢网络中起着关键作用，但它实际上通过不同途径控制体内代谢通量分布的程度基本上是未知的。基于细胞内通量的代谢范围的定量，我们系统地阐明了ArcA，ArcB，Cra，Crp，Cya，Fur和Mic在大肠杆菌分批培养中对需氧葡萄糖催化剂的全局转录调控的相关性。敲除的ArcB，Cra，毛皮，和Mlc的表型沉默，而删除的分解代谢产物阻遏监管机构的Crp和Cya导致一个明显的缓慢生长的表型，但只有一个非特异性的影响，实际通量分布。然而，敲除依赖于ArcA的氧化还原调节，使有氧三羧酸（TCA）循环活性增加了60%以上。像有氧条件下，厌氧去阻遏TCA循环酶在ArcA突变体显着增加了体内TCA流量时，硝酸盐作为电子受体。体内和体外数据表明，ArcA依赖的转录调控直接或间接地控制在有氧和厌氧葡萄糖分批培养的E.杆菌这种控制远远超出了以前已知的微需氧期间TCA循环的ArcA依赖性调节。
Even though transcriptional regulation plays a key role in establishing the metabolic network, the extent to which it actually controls the in vivo distribution of metabolic fluxes through different pathways is essentially unknown. Based on metabolism-wide quantification of intracellular fluxes, we systematically elucidated the relevance of global transcriptional regulation by ArcA, ArcB, Cra, Crp, Cya, Fur, and Mic for aerobic glucose catabolism in batch cultures of Escherichia coli. Knockouts of ArcB, Cra, Fur, and Mlc were phenotypically silent, while deletion of the catabolite repression regulators Crp and Cya resulted in a pronounced slow-growth phenotype but had only a nonspecific effect on the actual flux distribution. Knockout of ArcA-dependent redox regulation, however, increased the aerobic tricarboxylic acid (TCA) cycle activity by over 60%. Like aerobic conditions, anaerobic derepression of TCA cycle enzymes in an ArcA mutant significantly increased the in vivo TCA flux when nitrate was present as an electron acceptor. The in vivo and in vitro data demonstrate that ArcA-dependent transcriptional regulation directly or indirectly controls TCA cycle flux in both aerobic and anaerobic glucose batch cultures of E. coli. This control goes well beyond the previously known ArcA-dependent regulation of the TCA cycle during microaerobiosis.