This Article Full Text Full Text (PDF) Supplemental material Other Versions of this Article: JB.01910-07v1 190/8/3063    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Gao, H. Articles by Yang, R. PubMed PubMed Citation Articles by Gao, H. Articles by Yang, R.

 Previous Article  |  Next Article 

Journal of Bacteriology, April 2008, p. 3063-3075, Vol. 190, No. 8
0021-9193/08/$08.00+0     doi:10.1128/JB.01910-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

The Iron-Responsive Fur Regulon in Yersinia pestis ^,

He Gao,^1,2, Dongsheng Zhou,^2, Yingli Li,^2, Zhaobiao Guo,² Yanping Han,² Yajun Song,² Junhui Zhai,² Zongmin Du,² Xiaoyi Wang,² Jingmei Lu,^1* and Ruifu Yang^2*

College of Life Sciences, Northeast Normal University, Changchun 130024, People's Republic of China,¹ State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, People's Republic of China²

Received 6 December 2007/ Accepted 4 February 2008

The ferric uptake regulator (Fur) is a predominant bacterial regulator controlling the iron assimilation functions in response to iron availability. Our previous microarray analysis on Yersinia pestis defined the iron-Fur modulon. In the present work, we reannotated the iron assimilation genes in Y. pestis, and the resulting genes in complementation with those disclosed by microarray constituted a total of 34 genome loci (putative operons) that represent the potential iron-responsive targets of Fur. The subsequent real-time reverse transcription-PCR (RT-PCR) in conjunction with the primer extension analysis showed that 32 of them were regulated by Fur in response to iron starvation. A previously predicted Fur box sequence was then used to search against the promoter regions of the 34 operons; the homologue of the above box could be predicted in each promoter tested. The subsequent electrophoretic mobility shift assay (EMSA) demonstrated that a purified His₆ tag-fused Fur protein was able to bind in vitro to each of these promoter regions. Therefore, Fur is a global regulator, both an activator and a repressor, and directly controls not only almost all of the iron assimilation functions but also a variety of genes involved in various non-iron functions for governing a complex regulatory cascade in Y. pestis. In addition, real-time RT-PCR, primer extension, EMSA, and DNase I footprinting assay were used to elucidate the Fur regulation of the ybt locus encoding a virulence-required iron uptake system. By combining the published data on the YbtA regulation of ybt, we constructed a concise Fur/YbtA regulatory network with a map of the Fur-promoter DNA interactions within the ybt locus. The data presented here give us an overview of the iron-responsive Fur regulon in Y. pestis.

Published ahead of print on 15 February 2008.

Supplemental material for this article may be found at http://jb.asm.org/.

H.G., D.Z., and Y.L. contributed equally to this study.