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Global gene expression mediated by Thermus thermophilus SdrP, a CRP/FNR family transcriptional regulator
Author(s) -
Agari Yoshihiro,
Kashihara Aiko,
Yokoyama Shigeyuki,
Kuramitsu Seiki,
Shinkai Akeo
Publication year - 2008
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2008.06388.x
Subject(s) - thermus thermophilus , biology , regulator , genetics , transcriptional regulation , gene , gene expression , regulation of gene expression , microbiology and biotechnology , escherichia coli
Summary Thermus thermophilus SdrP is one of four cyclic AMP receptor protein (CRP)/fumarate and nitrate reduction regulator (FNR) family proteins from the extremely thermophilic bacterium T. thermophilus HB8. Expression of sdrP mRNA increased in the stationary phase during cultivation at 70°C. Although the sdrP gene was non‐essential, an sdrP ‐deficient strain showed growth defects, particularly when grown in a synthetic medium, and increased sensitivity to disulphide stress. The expression of several genes was altered in the sdrP disruptant. Among them, we found eight SdrP‐dependent promoters using in vitro transcription assays. A predicted SdrP binding site similar to that recognized by Escherichia coli CRP was found upstream of each SdrP‐dependent promoter. In the wild‐type strain, expression of these eight genes tended to increase upon entry into the stationary phase. Transcriptional activation in vitro was independent of any added effector molecule. The hypothesis that apo‐SdrP is the active form of the protein was supported by the observation that the three‐dimensional structure of apo‐SdrP is similar to that of the DNA‐binding form of E. coli CRP. Based on the properties of the SdrP‐regulated genes found in this study, it is speculated that SdrP is involved in nutrient and energy supply, redox control, and polyadenylation of mRNA.