Analyses of binding sequences of the PhaR protein of Rhodobacter sphaeroides FJ1
Analyses of binding sequences of the PhaR protein of Rhodobacter sphaeroides FJ1
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DOI：
10.1111/j.1574-6968.2009.01836.x
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发表时间：
2010-01-01
影响因子：
2.1
通讯作者：
Yang, Mei-Kwei
中科院分区：
文献类型：
--
作者：
Chou, Min-En;Yang, Mei-Kwei
phaC、phaP、phaR和phaZ基因参与聚-β-羟基丁酸酯（PHB）的合成、积累和降解。这些基因分别编码PHB合酶、相蛋白、调节蛋白和PHB解聚酶，并且位于Rhodobacter sphaeroides FJ 1基因组中的相同位点，Rhodobacter sphaeroides FJ 1是一种能够产生PHB的紫色非硫细菌。我们先前已经发现PhaR蛋白结合到phaP、phaR和phaZ的启动子区并抑制它们的表达。在这项研究中，我们确定PhaR与11-bp的回文序列5 '-CTGCN（3）GCAG-3'结合，该序列位于phaP翻译起始位点的-69至-59和-97至-87核苷酸处。用该序列中的任何三个或四个核苷酸取代三个间隔区核苷酸对PhaR结合没有影响，但该序列中的所有其他碱基缺失或取代都消除了其在体外和体内结合PhaR的能力。这些结果表明，PhaR调节phaP在R. sphaeroides FJ1.
The phaC, phaP, phaR, and phaZ genes are involved in the synthesis, accumulation, and degradation of poly-beta-hydroxybutyrate (PHB). These genes encode the PHB synthase, phasin, regulatory protein, and PHB depolymerase, respectively, and are located in the same locus in the genome of Rhodobacter sphaeroides FJ1, a purple nonsulfur bacterium capable of producing PHB. We have previously found that the PhaR protein binds to the promoter regions of phaP, phaR, and phaZ and represses their expression. In this study, we determined that PhaR binds to an 11-bp palindromic sequence, 5'-CTGCN(3)GCAG-3', located at nucleotides -69 to -59 and -97 to -87 relative to the translation start site of phaP. Substitution of the three spacer nucleotides with any three or four nucleotides in this sequence had no effect on PhaR binding, but all other base deletions or substitutions in this sequence abolished its ability to bind PhaR both in vitro and in vivo. These results suggest that PhaR regulates the expression of phaP in R. sphaeroides FJ1.