Differences in nitrate reduction between Mycobacterium tuberculosis and Mycobacterium bovis are due to differential expression of both narGHJI and narK2.

Abstract

Both Mycobacterium tuberculosis and Mycobacterium bovis can produce tuberculosis in humans. Mycobacterium tuberculosis has low nitrate reductase activity during aerobic growth (AG), but shows strong hypoxic induction. Virulent M. bovis has weak activity during AG with no hypoxic induction. Bacille Calmette-Guerin (BCG) lacks activity in both stages. Transcription of narG of the nitrate reductase enzyme operon was higher in M. tuberculosis than in M. bovis or BCG. Transcription of narK2 encoding the nitrate transporter was induced by hypoxia in M. tuberculosis but not M. bovis or BCG. Insertion of the M. tuberculosis narGHJI operon into M. bovis resulted in increased activity only during AG. Regulation of both the nitrate reductase enzyme and transporter are regulated differently in the two species.

• Authors: Charles D Sohaskey, Lucia Modesti
• Journal: FEMS microbiology letters (FEMS Microbiol Lett) Vol. 290 Issue 2 Pg. 129-34 (Jan 2009) ISSN: 1574-6968 [Electronic] England
• PMID: 19076631 (Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Anion Transport Proteins
• Bacterial Proteins
• Nitrate Transporters
• Nitrates
• Nitrate Reductase

Topics

• Aerobiosis
• Anion Transport Proteins (genetics, metabolism)
• Bacterial Proteins (genetics, metabolism)
• Cloning, Molecular
• Gene Expression Regulation, Bacterial
• Humans
• Mycobacterium bovis (enzymology, genetics, pathogenicity)
• Mycobacterium tuberculosis (enzymology, genetics, pathogenicity)
• Nitrate Reductase (genetics, metabolism)
• Nitrate Transporters
• Nitrates (metabolism)
• Operon
• Oxidation-Reduction
• Tuberculosis (microbiology)
• Virulence