In:
Microbiology, Microbiology Society, Vol. 160, No. 12 ( 2014-12-01), p. 2650-2660
Abstract:
LdrP (TT_P0055) (LitR-dependent regulatory protein) is one of the four cAMP receptor protein (CRP)/FNR family transcriptional regulators retained by the extremely thermophilic bacterium Thermus thermophilus . Previously, we reported that LdrP served as a positive regulator for the light-induced transcription of crtB , a carotenoid biosynthesis gene encoded on the megaplasmid of this organism. Here, we showed that LdrP also functions as an activator of the expression of genes clustered around the crtB gene under the control of LitR, an adenosyl B 12 -bound light-sensitive regulator. Transcriptome analysis revealed the existence of 19 LitR-dependent genes on the megaplasmid. S1 nuclease protection assay confirmed that the promoters preceding TT_P0044 (P 44 ), TT_P0049 (P 49 ) and TT_P0070 (P 70 ) were activated upon illumination in the WT strain. An ldrP mutant lost the ability to activate P 44 , P 49 and P 70 , whilst disruption of litR resulted in constitutive transcription from these promoters irrespective of illumination, indicating that these genes were photo-dependently regulated by LdrP and LitR. An in vitro transcription experiment demonstrated that LdrP directly activated mRNA synthesis from P 44 and P 70 by the Thermus RNA polymerase holocomplex. The present evidence indicated that LdrP was the positive regulator essential for the transcription of the T. thermophilus light-inducible cluster encoded on the megaplasmid.
Type of Medium:
Online Resource
ISSN:
1350-0872
,
1465-2080
DOI:
10.1099/mic.0.082263-0
Language:
English
Publisher:
Microbiology Society
Publication Date:
2014
detail.hit.zdb_id:
2008736-6
SSG:
12
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