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Title: Iron limitation in Mycobacterium tuberculosis: studies on iron-regulated envelope proteins & catalase-peroxidases
Researcher: Yeruva, Chaitanya Veena
Guide(s): Sritharan, Manjula
Keywords: Animal Science
Life Science
Mycobacterium tuberculosis
Upload Date: 14-Aug-2012
University: University of Hyderabad
Completed Date: March 2009
Abstract: Mycobacterium tuberculosis is the causative agent of tuberculosis in humans. Despite several advances in the control of the disease, tuberculosis remains a public concern globally. A better understanding of host-pathogen interaction is required for effective control measures including diagnosis and development of new and better vaccines. Iron is one of the contributing factors to the virulence of the pathogen. Mycobacteria have adapted to iron deprivation by elaboration of two siderophores, the intracellular mycobactin and extra cellular carboxymycobactin / exochelin and their receptors, the iron-regulated envelope proteins (IREPS). IREPS were first demonstrated in M. smegmatis, with a 29 kDa protein shown to be the ferric-exochelin receptor. Though iron-regulated proteins were identified in M. tuberculosis, no specific envelope proteins were identified upon iron limitation. The genome of M. tuberculosis shows the presence of at least four iron regulators, of which IdeR and FurA are experimentally verified. Though studies with ideR mutants confirmed the role of the IdeR in iron homeostasis, it appears that it is not the sole regulator and that iron-regulation is more complex than envisaged in mycobacteria. FurA, encoded by furA, located immediately upstream of katG encoding catalase-peroxidase controls the expression of KatG, though the association with iron levels remains to be ascertained. The focus of the present study was to understand the effect of iron deprivation in M. tuberculosis and covered two major objectives. First, the effect of iron deprivation on the iron acquisition machinery was analysed and second, the influence of iron levels on catalase-peroxidase was studied. Growth of M. tuberculosis under low iron conditions showed the coordinate expression of both the siderophores and a 28 kDa cell wall-associated iron-regulated protein (Irep-28). Sequence analysis identified Irep-28 as the DNA-binding HU homologue HupB protein (hupB [Rv2986c])..
Pagination: 229p.
Appears in Departments:School of life Sciences

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02_certificate.pdf33.63 kBAdobe PDFView/Open
03_acknowledgements.pdf66.77 kBAdobe PDFView/Open
04_contents.pdf77.71 kBAdobe PDFView/Open
05_list of abbreviations.pdf32.12 kBAdobe PDFView/Open
06_abstract.pdf35.85 kBAdobe PDFView/Open
07_chapter 1.pdf1.62 MBAdobe PDFView/Open
08_chapter 2.pdf494.59 kBAdobe PDFView/Open
09_chapter 3.pdf2.94 MBAdobe PDFView/Open
10_chapter 4.pdf203.97 kBAdobe PDFView/Open
11_chapter 5.pdf52.24 kBAdobe PDFView/Open
12_chapter 6.pdf173.78 kBAdobe PDFView/Open

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