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
Item Type: | Article |
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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: | 10.1128/JB.00672-09 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:9826 |
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