A single nucleotide change affects fur-dependent regulation of sodB in H. pylori.
A single nucleotide change affects fur-dependent regulation of sodB in H. pylori.
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DOI：
10.1371/journal.pone.0005369
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发表时间：
2009
期刊：
影响因子：
3.7
通讯作者：
Merrell DS
中科院分区：
文献类型：
--
作者：
Carpenter BM;Gancz H;Gonzalez-Nieves RP;West AL;Whitmire JM;Michel SL;Merrell DS
幽门螺杆菌是一种重要的人类病原体，它已经适应了胃环境中的许多压力。超氧化物歧化酶（SodB）是帮助幽门螺杆菌对抗氧化应激的重要因子。先前表明，在没有铁（apo-Fur 调节）的情况下，sodB 会受到铁吸收调节器（Fur）的抑制。在此，我们表明 apo 调节在所有幽门螺杆菌菌株中并不完全保守。在幽门螺杆菌菌株 G27、HPAG1 或 J99 中，在缺铁条件下未观察到 sodB 表达的 apo-Fur 依赖性变化。然而，Fur 对 pfr 和 amiE 的调节如预期发生。 G27 和 26695 之间的 Fur 编码序列的比较分析揭示了单个氨基酸差异，这并不是 sodB 调节改变的原因。 G27 和 26695 的 sodB 启动子的比较还揭示了预测的 Fur 结合位点内的单核苷酸差异。将 G27 中的该核苷酸改变为 26695 的核苷酸恢复了 apo-Fur 依赖性 sodB 调节，表明单碱基差异至少部分原因是在这些幽门螺杆菌菌株中观察到的 sodB 调节差异。 Fur 结合研究表明，G27 中该单核苷酸的改变增加了 Fur 对 sodB 启动子的亲和力。此外，G27 中的单碱基变化使 sodB 启动子能够以类似于 26695 sodB 启动子的亲和力与 apo-Fur 结合。综上所述，这些数据表明该核苷酸残基对于 apo-Fur 与 sodB 启动子的直接结合非常重要。
Helicobacter pylori is a significant human pathogen that has adapted to survive the many stresses found within the gastric environment. Superoxide Dismutase (SodB) is an important factor that helps H. pylori combat oxidative stress. sodB was previously shown to be repressed by the Ferric Uptake Regulator (Fur) in the absence of iron (apo-Fur regulation). Herein, we show that apo regulation is not fully conserved among all strains of H. pylori. apo-Fur dependent changes in sodB expression are not observed under iron deplete conditions in H. pylori strains G27, HPAG1, or J99. However, Fur regulation of pfr and amiE occurs as expected. Comparative analysis of the Fur coding sequence between G27 and 26695 revealed a single amino acid difference, which was not responsible for the altered sodB regulation. Comparison of the sodB promoters from G27 and 26695 also revealed a single nucleotide difference within the predicted Fur binding site. Alteration of this nucleotide in G27 to that of 26695 restored apo-Fur dependent sodB regulation, indicating that a single base difference is at least partially responsible for the difference in sodB regulation observed among these H. pylori strains. Fur binding studies revealed that alteration of this single nucleotide in G27 increased the affinity of Fur for the sodB promoter. Additionally, the single base change in G27 enabled the sodB promoter to bind to apo-Fur with affinities similar to the 26695 sodB promoter. Taken together these data indicate that this nucleotide residue is important for direct apo-Fur binding to the sodB promoter.
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影响因子：
3.5
作者：
Cormack, BP;Valdivia, RH;Falkow, S
通讯作者：
Falkow, S
影响因子：
3.6
作者：
Delany, I;Spohn, G;Scarlato, V
通讯作者：
Scarlato, V
DOI：
10.1073/pnas.90.12.5791
发表时间：
1993-06-15
影响因子：
11.1
作者：
COVACCI, A;CENSINI, S;RAPPUOLI, R
通讯作者：
RAPPUOLI, R
影响因子：
3.2
作者：
Gancz, Hanan;Jones, Kathleen R.;Merrell, D. Scott
通讯作者：
Merrell, D. Scott
影响因子：
5.8
作者：
Gieseler, S;König, B;Backert, S
通讯作者：
Backert, S