This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow E-mail this article to a friend
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
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Yamada, K.
Right arrow Articles by Itoh, Y.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Yamada, K.
Right arrow Articles by Itoh, Y.
Agricola
Right arrow Articles by Yamada, K.
Right arrow Articles by Itoh, Y.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, October 2008, p. 6017-6025, Vol. 74, No. 19
0099-2240/08/$08.00+0     doi:10.1128/AEM.01297-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Binding Sequences for RdgB, a DNA Damage-Responsive Transcriptional Activator, and Temperature-Dependent Expression of Bacteriocin and Pectin Lyase Genes in Pectobacterium carotovorum subsp. carotovorum{triangledown} ,{dagger}

Kazuteru Yamada, Jun Kaneko, Yoshiyuki Kamio,{ddagger} and Yoshifumi Itoh*

Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori Amamiya-machi 1-1, Aoba-ku, Sendai 981-8555, Japan

Received 10 June 2008/ Accepted 31 July 2008

Pectobacterium carotovorum subsp. carotovorum strain Er simultaneously produces the phage tail-like bacteriocin carotovoricin (Ctv) and pectin lyase (Pnl) in response to DNA-damaging agents. The regulatory protein RdgB of the Mor/C family of proteins activates transcription of pnl through binding to the promoter. However, the optimal temperature for the synthesis of Ctv (23°C) differs from that for synthesis of Pnl (30°C), raising the question of whether RdgB directly activates ctv transcription. Here we report that RdgB directly regulates Ctv synthesis. Gel mobility shift assays demonstrated RdgB binding to the P0, P1, and P2 promoters of the ctv operons, and DNase I footprinting determined RdgB-binding sequences (RdgB boxes) on these and on the pnl promoters. The RdgB box of the pnl promoter included a perfect 7-bp inverted repeat with high binding affinity to the regulator (Kd [dissociation constant] = 150 nM). In contrast, RdgB boxes of the ctv promoters contained an imperfect inverted repeat with two or three mismatches that consequently reduced binding affinity (Kd = 250 to 350 nM). Transcription of the rdgB and ctv genes was about doubled at 23°C compared with that at 30°C. In contrast, the amount of pnl transcription tripled at 30°C. Thus, the inverse synthesis of Ctv and Pnl as a function of temperature is apparently controlled at the transcriptional level, and reduced rdgB expression at 30°C obviously affected transcription from the ctv promoters with low-affinity RdgB boxes. Pathogenicity toward potato tubers was reduced in an rdgB knockout mutant, suggesting that the RdgAB system contributes to the pathogenicity of this bacterium, probably by activating pnl expression.

* Corresponding author. Mailing address: Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori Amamiya-machi 1-1, Aoba-ku, Sendai 981-8555, Japan. Phone: 81-22-717-8779. Fax: 81-22-717-8780. E-mail: yosifumi{at}biochem.tohoku.ac.jp

{triangledown} Published ahead of print on 8 August 2008.

{dagger} Supplemental material for this article may be found at http://aem.asm.org/.

{ddagger} Present address: Department of Human Health and Nutrition, Graduate School of Comprehensive Human Sciences, Shokei Gakuin University, Yurigaoka 4-10-1, Natori 981-1295, Japan.

Applied and Environmental Microbiology, October 2008, p. 6017-6025, Vol. 74, No. 19
0099-2240/08/$08.00+0     doi:10.1128/AEM.01297-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.





Copyright © 2010 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»