GlpR Is a Direct Transcriptional Repressor of Fructose Metabolic Genes in Haloferax volcanii
GlpR Is a Direct Transcriptional Repressor of Fructose Metabolic Genes in Haloferax volcanii
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DOI：
10.1128/jb.00244-18
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发表时间：
2018-06
影响因子：
3.2
通讯作者：
Jonathan H. Martin;Katherine Sherwood Rawls;J. C. Chan;Sungmin Hwang;M. Martínez-Pastor;Lana J. McMillan;Laurence Prunetti;Amy K. Schmid;J. Maupin-Furlow
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文献类型：
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作者：
Jonathan H. Martin;Katherine Sherwood Rawls;J. C. Chan;Sungmin Hwang;M. Martínez-Pastor;Lana J. McMillan;Laurence Prunetti;Amy K. Schmid;J. Maupin-Furlow
许多古生菌是极端微生物，能够在极端盐度、pH和温度的生境中茁壮成长。这些生物特性是生物技术应用的理想选择。然而，对古生菌新陈代谢的有限知识是阻碍古生菌作为工业产品微生物工厂广泛使用的瓶颈。在这里，我们描述了一个生活在高盐度中的物种是如何调节糖的吸收和使用的。我们使用与远亲细菌物种保守的分子机制证明了该古菌物种中的一个关键的糖调节蛋白的功能。摘要Deor-type Helix-Turn-Helix(HTH)结构域蛋白是多种细菌中糖和核苷代谢的转录调节蛋白，也存在于特定的古生菌中。在模型考古子Haloferax Volcanii中，以前的工作涉及Deor型转录调控因子GlpR在甘油生长过程中对glpR和编码果糖特异性磷酸果糖激酶(PfkB)的基因的转录抑制。然而，由GlpR管理的全球监管仍不清楚。在这里，我们比较了生长在甘油和葡萄糖上的野生型和ΔGlpR突变株的转录水平，以检测近50个受GlpR调控的新基因的显著转录水平差异。通过对GlpR结合序列的计算预测与体内和体外的DNA结合实验相结合，我们确定GlpR直接控制参与果糖降解的酶的编码基因，包括糖酵解的中央控制点果糖二磷酸缩醛酶。GlpR还直接控制其他转录因子。相反，其他代谢途径似乎受到GlpR的间接影响。体外实验证明，GlpR可以作为四聚体与效应分子果糖-1-磷酸(F1P)结合。这些结果表明，在果糖以外的碳源(如葡萄糖和甘油)上生长过程中，H.Volcanii GlpR作为果糖降解的直接负调节因子发挥作用，并且GlpR与细菌Deor型调节因子具有惊人的功能相似性。许多古生菌是极端微生物，能够在极端盐度、酸碱度和温度的生境中茁壮成长。这些生物特性是生物技术应用的理想选择。然而，对古生菌新陈代谢的有限知识是阻碍古生菌作为工业产品微生物工厂广泛使用的瓶颈。在这里，我们描述了一个生活在高盐度中的物种是如何调节糖的吸收和使用的。我们使用与远亲细菌物种保守的分子机制证明了该古菌物种中的一个关键的糖调节蛋白的功能。
Many archaea are extremophiles, able to thrive in habitats of extreme salinity, pH and temperature. These biological properties are ideal for applications in biotechnology. However, limited knowledge of archaeal metabolism is a bottleneck that prevents the broad use of archaea as microbial factories for industrial products. Here, we characterize how sugar uptake and use are regulated in a species that lives in high salinity. We demonstrate that a key sugar regulatory protein in this archaeal species functions using molecular mechanisms conserved with distantly related bacterial species. ABSTRACT DeoR-type helix-turn-helix (HTH) domain proteins are transcriptional regulators of sugar and nucleoside metabolism in diverse bacteria and also occur in select archaea. In the model archaeon Haloferax volcanii, previous work implicated GlpR, a DeoR-type transcriptional regulator, in the transcriptional repression of glpR and the gene encoding the fructose-specific phosphofructokinase (pfkB) during growth on glycerol. However, the global regulon governed by GlpR remained unclear. Here, we compared transcriptomes of wild-type and ΔglpR mutant strains grown on glycerol and glucose to detect significant transcript level differences for nearly 50 new genes regulated by GlpR. By coupling computational prediction of GlpR binding sequences with in vivo and in vitro DNA binding experiments, we determined that GlpR directly controls genes encoding enzymes involved in fructose degradation, including fructose bisphosphate aldolase, a central control point in glycolysis. GlpR also directly controls other transcription factors. In contrast, other metabolic pathways appear to be under the indirect influence of GlpR. In vitro experiments demonstrated that GlpR purifies to function as a tetramer that binds the effector molecule fructose-1-phosphate (F1P). These results suggest that H. volcanii GlpR functions as a direct negative regulator of fructose degradation during growth on carbon sources other than fructose, such as glucose and glycerol, and that GlpR bears striking functional similarity to bacterial DeoR-type regulators. IMPORTANCE Many archaea are extremophiles, able to thrive in habitats of extreme salinity, pH and temperature. These biological properties are ideal for applications in biotechnology. However, limited knowledge of archaeal metabolism is a bottleneck that prevents the broad use of archaea as microbial factories for industrial products. Here, we characterize how sugar uptake and use are regulated in a species that lives in high salinity. We demonstrate that a key sugar regulatory protein in this archaeal species functions using molecular mechanisms conserved with distantly related bacterial species.