This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Google Scholar
Right arrow Articles by Lennon, C. W.
Right arrow Articles by Gourse, R. L.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lennon, C. W.
Right arrow Articles by Gourse, R. L.

 Previous Article  |  Next Article 

Journal of Bacteriology, September 2009, p. 5854-5858, Vol. 191, No. 18
0021-9193/09/$08.00+0     doi:10.1128/JB.00621-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Escherichia coli DksA Binds to Free RNA Polymerase with Higher Affinity than to RNA Polymerase in an Open Complex{triangledown}

Christopher W. Lennon, Tamas Gaal, Wilma Ross, and Richard L. Gourse*

Department of Bacteriology, University of Wisconsin—Madison, 1550 Linden Drive, Madison, Wisconsin 53706

Received 12 May 2009/ Accepted 13 July 2009

The transcription factor DksA binds in the secondary channel of RNA polymerase (RNAP) and alters transcriptional output without interacting with DNA. Here we present a quantitative assay for measuring DksA binding affinity and illustrate its utility by determining the relative affinities of DksA for three different forms of RNAP. Whereas the apparent affinities of DksA for RNAP core and holoenzyme are the same, the apparent affinity of DksA for RNAP decreases almost 10-fold in an open complex. These results suggest that the conformation of RNAP present in an open complex is not optimal for DksA binding and that DNA directly or indirectly alters the interface between the two proteins.

* Corresponding author. Mailing address: Department of Bacteriology, University of Wisconsin—Madison, 1550 Linden Drive, Madison, WI 53706. Phone: (608) 262-9813. Fax: (608) 262-9865. E-mail: rgourse{at}bact.wisc.edu

{triangledown} Published ahead of print on 17 July 2009.

Journal of Bacteriology, September 2009, p. 5854-5858, Vol. 191, No. 18
0021-9193/09/$08.00+0     doi:10.1128/JB.00621-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»