A novel aerobactin utilization cluster in Vibrio vulnificus with a gene involved in the transcription regulation of the iutA homologue

被引:33
作者
Tanabe, T
Naka, A
Aso, H
Nakao, H
Narimatsu, S
Inoue, Y
Ono, T
Yamamoto, S
机构
[1] Okayama Univ, Fac Pharmaceut Sci, Grad Sch Med Dent & Pharmaceut Sci, Dept Mol Biopharmaceut Sci, Okayama 7008530, Japan
[2] Kumamoto Univ, Grad Sch Med Sci, Dept Dermatol, Kumamoto 8608556, Japan
关键词
aerobactin utilization gene cluster; ABC transport system; iron-regulated gene; transcription regulation;
D O I
10.1111/j.1348-0421.2005.tb03671.x
中图分类号
R392 [医学免疫学]; Q939.91 [免疫学];
学科分类号
100102 ;
摘要
We demonstrated that Vibrio vulnificus M2799 utilizes aerobactin for growth as an exogenous siderophore under iron-limiting conditions, concomitant with enhanced production of the 76-kDa iron-repressible outer membrane protein. Subsequently, by applying the Fur titration assay method to the M2799 genomic libraries followed by further cloning of the regions surrounding the candidate genes, we identified the 8.4-kb aerobactin utilization gene cluster which consists of five genes arranged in three distinct transcriptional units. It was confirmed by disruption of the corresponding genes that the first unit forming a three-gene operon (vatCDB) and the third unit of a single gene (iutA) encode an ATP-binding cassette transport component and the 76-kDa ferric aerobactin receptor, respectively. The second unit of another single gene (iutR), encodes a homologue of the GntR family of transcriptional repressors. Although transcription of the first and third units was iron-regulated, the iutR gene was transcribed regardless of iron status in the growth medium. Construction of an iutR disruptant coupled with genetic complementation experiments suggested that the gene encodes a transcriptional repressor for iutA. This is the first example of a regulator gene involved in aerobactin-enhanced production of IutA.
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页码:823 / 834
页数:12
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