In:
Microbiology, Microbiology Society, Vol. 157, No. 2 ( 2011-02-01), p. 419-429
Kurzfassung:
The ferric uptake regulator Fur has been reported to repress the expression of rmpA , a regulatory gene for the mucoid phenotype, leading to decreased capsular polysaccharide (CPS) biosynthesis in Klebsiella pneumoniae CG43. Here, quantitative real-time PCR (qRT-PCR) analyses and electrophoretic mobility shift assays showed that Fur also repressed the expression of the CPS regulatory genes rmpA2 and rcsA . Interestingly, deletion of rmpA or rcsA but not rmpA2 from the Δ fur strain was able to suppress the deletion effect of Fur. The availability of extracellular iron affected the amount of CPS, suggesting that Fur regulates CPS biosynthesis in an Fe(II)-dependent manner. Increased production of siderophores was observed in the Δ fur strain, suggesting that uptake of extracellular iron in K. pneumoniae is regulated by Fur. Fur titration assays and qRT-PCR analyses demonstrated that at least six of the eight putative iron-acquisition systems, identified by a blast search in the contig database of K. pneumoniae CG43, were directly repressed by Fur. We conclude that Fur has a dual role in the regulation of CPS biosynthesis and iron acquisition in K. pneumoniae .
Materialart:
Online-Ressource
ISSN:
1350-0872
,
1465-2080
DOI:
10.1099/mic.0.044065-0
Sprache:
Englisch
Verlag:
Microbiology Society
Publikationsdatum:
2011
ZDB Id:
2008736-6
SSG:
12
