Papers by Dipankar Chatterjee
Microbiology, 2009
Rifampicin and its derivatives are at the forefront of the current standard chemotherapeutic regi... more Rifampicin and its derivatives are at the forefront of the current standard chemotherapeutic regimen for active tuberculosis; they act by inhibiting the transcription activity of prokaryotic RNA polymerase. Rifampicin is believed to interact with the β subunit of RNA polymerase. However, it has been observed that protein–protein interactions with RNA polymerase core enzyme lead to its reduced susceptibility to rifampicin. This mechanism became more diversified with the discovery of RbpA, a novel RNA polymerase-binding protein, in Streptomyces coelicolor that could mitigate the effect of rifampicin on RNA polymerase activity. MsRbpA is a homologue of RbpA in Mycobacterium smegmatis. On deciphering the role of MsRbpA in M. smegmatis we found that it interacts with RNA polymerase and increases the rifampicin tolerance levels, both in vitro and in vivo. It interacts with the β subunit of RNA polymerase. However, it was found to be incapable of rescuing rifampicin-resistant RNA polymeras...
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Journal of Biosciences, 1993
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FEBS Letters, 1990
Binding of Escherichia coli RNA polymerase and the abortive initiation of transcription at the A2... more Binding of Escherichia coli RNA polymerase and the abortive initiation of transcription at the A2 promoter ofbacteriophage T7, separately cloned in pBR322, was found to be strongly dependent on the degree of supercoiling of the plasmid. Supercoiling does not seem to play any role in the initiation of transcription at the T7A1 promoter under identical conditions. Plasmid containing T7A2 promoter was found to be less amenable to S1 nuclease in comparison to that having T7A1. Sequence comparison reveals a high G/C content upstream to the −35 region of T7A2 which by extra duplex stability probably renders the initiation of transcription more dependent on the state of supercoiling of the template.
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FEBS Letters, 1985
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Infection and Immunity, 2000
Almost one-third of the world population today harbors the tubercle bacillus asymptomatically. It... more Almost one-third of the world population today harbors the tubercle bacillus asymptomatically. It is postulated that the morphology and staining pattern of the long-term persistors are different from those of actively growing culture. Interestingly, it has been found that the morphology and staining pattern of the starved in vitro population of mycobacteria is similar to the persistors obtained from the lung lesions. In order to delineate the biochemical characteristics of starved mycobacteria, Mycobacteria smegmatis was grown in 0.2% glucose as a sole carbon source along with an enriched culture in 2% glucose. Accumulation of the stringent factor guanosine tetraphosphate (ppGpp) with a concomitant change in morphology was observed for M. smegmatis under carbon-deprived conditions. In addition, M. smegmatis assumed a coccoid morphology when ppGpp was ectopically produced by overexpressing Escherichia coli relA , even in an enriched medium. The Mycobacterium tuberculosis relA and spo...
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Journal of Biosciences, 1980
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Journal of Biosciences, Sep 1, 1980
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Papers by Dipankar Chatterjee