Regulation of Aerobic and Anaerobic D-Malate Metabolism of Escherichia coli by the LysR-Type Regulator DmlR (YeaT)
Regulation of Aerobic and Anaerobic D-Malate Metabolism of Escherichia coli by the LysR-Type Regulator DmlR (YeaT)
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DOI：
10.1128/jb.01665-09
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发表时间：
2010-05-15
影响因子：
3.2
通讯作者：
Unden, Gottfried
中科院分区：
文献类型：
--
作者：
Lukas, Hanna;Reimann, Julia;Unden, Gottfried
大肠杆菌K-12能够在需氧条件下在D-苹果酸上生长，使用DctA吸收D-苹果酸，并使用D-苹果酸脱氢酶DmlA（以前的YeaU）将D-苹果酸转化为丙酮酸。诱导dmlA编码DmlA需要一个完整的dmlR（以前的yeaT）基因，它编码DmlR，一个LysR型转录调节因子。DmlR诱导dmlA需要D-苹果酸或L-或内消旋酒石酸的存在，但只有D-苹果酸支持需氧生长。一般C-4-二羧酸代谢调节剂（DcuS-DcuR双组分系统）对dmlA表达有一定影响。厌氧L-酒石酸调节剂TtdR或氧传感器ArcB-ArcA和FNR对dmlA表达没有主要影响。DmlR与TtdR具有高水平的序列同一性（49%），TtdR是E.杆菌dmlA在厌氧条件下也以高水平表达，并且细菌具有D-苹果酸脱氢酶活性。然而，这些细菌不能在D-苹果酸上生长，因为D-苹果酸降解的厌氧途径具有预测的产率，
Escherichia coli K-12 is able to grow under aerobic conditions on D-malate using DctA for D-malate uptake and the D-malate dehydrogenase DmlA (formerly YeaU) for converting D-malate to pyruvate. Induction of dmlA encoding DmlA required an intact dmlR (formerly yeaT) gene, which encodes DmlR, a LysR-type transcriptional regulator. Induction of dmlA by DmlR required the presence of D-malate or L- or meso-tartrate, but only D-malate supported aerobic growth. The regulator of general C-4-dicarboxylate metabolism (DcuS-DcuR two-component system) had some effect on dmlA expression. The anaerobic L- tartrate regulator TtdR or the oxygen sensors ArcB-ArcA and FNR did not have a major effect on dmlA expression. DmlR has a high level of sequence identity (49%) with TtdR, the L- and meso-tartrate-specific regulator of L- tartrate fermentation in E. coli. dmlA was also expressed at high levels under anaerobic conditions, and the bacteria had D-malate dehydrogenase activity. These bacteria, however, were not able to grow on D-malate since the anaerobic pathway for D-malate degradation has a predicted yield of