Up-regulation of narX, encoding a putative 'fused nitrate reductase' in anaerobic dormant Mycobacterium bovis BCG.
Mycobacterium tuberculosis and its closely related but non-pathogenic relative M. bovis Bacille Calmette-Guèrin (BCG) have the capability to adapt to anaerobiosis by shifting down from aerobic growth to a state of non-replicating persistence or dormancy. Here, we report the results of a comparative Northern analysis of 23 genes identified in the tubercle bacillus genome project that might play a role in the energy metabolism under anaerobic conditions. The expression of a majority of the genes was found to be down-regulated in the dormant BCG culture. However, the mRNA level for narX, a putative 'fused nitrate reductase' not found in other bacteria, was strongly up-regulated in anaerobic dormant bacilli. narX is the first transcriptionally induced gene in anaerobic dormant mycobacteria and might be a useful marker for monitoring the dormancy response in infected animals.
Hutter
B
B
Institute of Molecular and Cell Biology, Singapore, Singapore.
Dick
T
T
D000693:Anaerobiosis / Q000235:genetics; D001483:Base Sequence; D015152:Blotting, Northern; D004734:Energy Metabolism / Q000235:genetics; D029968:Escherichia coli Proteins; D008969:Molecular Sequence Data; D009163:Mycobacterium bovis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D016133:Polymerase Chain Reaction; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D012329:RNA, Bacterial / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D015854:Up-Regulation
D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D011494:Protein Kinases; C074787:narX protein, E coli