文章基本信息

标题：Transcriptional activation by MafR, a global regulator of Enterococcus faecalis
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作者：Sofía Ruiz-Cruz ; Ana Moreno-Blanco ; Manuel Espinosa 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2019
卷号：9
期号：1
页码：1-12
DOI：10.1038/s41598-019-42484-4
出版社：Springer Nature
摘要：Proteins that act as global transcriptional regulators play key roles in bacterial adaptation to new niches. These proteins recognize multiple DNA sites across the bacterial genome by different mechanisms. Enterococcus faecalis is able to survive in various niches of the human host, either as a commensal or as a leading cause of serious infections. Nonetheless, the regulatory pathways involved in its adaptive responses remain poorly understood. We reported previously that the MafR protein of E. faecalis causes genome-wide changes in the transcriptome. Here we demonstrate that MafR functions as a transcription activator. In vivo, MafR increased the activity of the P12294 and P11486 promoters and also the transcription levels of the two genes controlled by those promoters. These genes are predicted to encode a calcium-transporting P-type ATPase and a QueT transporter family protein, respectively. Thus, MafR could have a regulatory role in calcium homeostasis and queuosine synthesis. Furthermore, MafR recognized in vitro specific DNA sites that overlap the -35 element of each target promoter. The MafR binding sites exhibit a low sequence identity, suggesting that MafR uses a shape readout mechanism to achieve DNA-binding specificity.