Husnain, S., Busby, S.J.W. and Thomas, M.S. (2009) Downregulation of the Escherichia coli guaB promoter by upstream-bound cyclic AMP receptor protein. Journal of Bacteriology, 191 (19). pp. 6094-6104. ISSN 0021-9193
Abstract
The Escherichia coli guaB promoter (P-guaB) is responsible for directing transcription of the guaB and guaA genes, which specify the biosynthesis of the nucleotide GMP. P-guaB is subject to growth rate-dependent control (GRDC) and possesses an UP element that is required for this regulation. In addition, PguaB contains a discriminator, three binding sites for the nucleoid-associated protein FIS, and putative binding sites for the regulatory proteins DnaA, PurR, and cyclic AMP receptor protein (CRP). Here we show that the CRP-cyclic AMP (cAMP) complex binds to a site located over 100 bp upstream of the guaB transcription start site, where it serves to downregulate P-guaB. The CRP-mediated repression of P-guaB activity increases in media that support lower growth rates. Inactivation of the crp or cyaA gene or ablation/translocation of the CRP site relieves repression by CRP and results in a loss of GRDC of P-guaB. Thus, GRDC of P-guaB involves a progressive increase in CRP-mediated repression of the promoter as the growth rate decreases. Our results also suggest that the CRP-cAMP complex does not direct GRDC at P-guaB and that at least one other regulatory factor is required for conferring GRDC on this promoter. However, PurR and DnaA are not required for this regulatory mechanism.
Metadata
Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2009 American Society of Microbiology. This is an author produced version of a paper subsequently published in Journal of Bacteriology. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | C-Terminal Domain; Rate-Dependent Regulation; Catabolite Activator Protein; Ribosomal-RNA Transcription; Polymerase Alpha-Subunit; Growth-Rate Regulation; Bacterial Transcription; Nucleoprotein Complexes; Negative Control; Cloning Vectors |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) > Department of Biomedical Science (Sheffield) The University of Sheffield > Faculty of Medicine, Dentistry and Health (Sheffield) > The Medical School (Sheffield) |
Depositing User: | Miss Anthea Tucker |
Date Deposited: | 06 Oct 2009 13:57 |
Last Modified: | 08 Feb 2013 16:59 |
Published Version: | http://dx.doi.org/10.1128/JB.00672-09 |
Status: | Published |
Publisher: | American Society of Microbiology |
Refereed: | Yes |
Identification Number: | https://doi.org/10.1128/JB.00672-09 |
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