Pandey, S.D. and Choudhury, Mitali and Yousuf, S. and Wheeler, P.R. and Gordon, S.V. and Ranjan, Akash and Sritharan, Manjula (2014) Iron-Regulated Protein HupB of Mycobacterium tuberculosis Positively Regulates Siderophore Biosynthesis and Is Essential for Growth in Macrophages. Journal of Bacteriology, 196 (10). pp. 1853-1865. ISSN 0021-9193

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Abstract

Mycobacterium tuberculosis expresses the 28-kDa protein HupB (Rv2986c) and the Fe3+-specific high-affinity siderophores mycobactin and carboxymycobactin upon iron limitation. The objective of this study was to understand the functional role of HupB in iron acquisition. A hupB mutant strain of M. tuberculosis, subjected to growth in low-iron medium (0.02 μg Fe ml−1), showed a marked reduction of both siderophores with low transcript levels of the mbt genes encoding the MB biosynthetic machinery. Complementation of the mutant strain with hupB restored siderophore production to levels comparable to that of the wild type. We demonstrated the binding of HupB to the mbtB promoter by both electrophoretic mobility shift assays and DNA footprinting. The latter revealed the HupB binding site to be a 10-bp AT-rich region. While negative regulation of the mbt machinery by IdeR is known, this is the first report of positive regulation of the mbt operon by HupB. Interestingly, the mutant strain failed to survive inside macrophages, suggesting that HupB plays an important role in vivo

Item Type:	Article
Subjects:	Genetics Molecular Biology
Depositing User:	Users 2 not found.
Date Deposited:	23 May 2015 20:17
Last Modified:	28 Nov 2017 19:06
URI:	http://cdfd.sciencecentral.in/id/eprint/81

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