This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dziadek, J. Articles by Madiraju, M. V. V. S. Search for Related Content PubMed PubMed Citation Articles by Dziadek, J. Articles by Madiraju, M. V. V. S.

Mutations in the CCGTTCACA DnaA Box of Mycobacterium tuberculosis oriC That Abolish Replication of oriC Plasmids Are Tolerated on the Chromosome

Department of Biochemistry, The University of Texas Health Center at Tyler, Tyler, Texas 75708-3154,¹ Department of Medical Microbiology, Barts and the London, Queen Mary's School of Medicine and Dentistry, Whitechapel, London E1 2AA, United Kingdom,² Public Health Research Institute Tuberculosis Center, Newark, New Jersey 07103³

Received 29 March 2001/ Accepted 24 April 2002

The origin of replication (oriC) region in some clinical strains of Mycobacterium tuberculosis is a hot spot for IS6110 elements. To understand how clinical strains with insertions in oriC can replicate their DNA, we characterized the oriC regions of some clinical strains. Using a plasmid-based oriC-dependent replication assay, we showed that IS6110 insertions that disrupted the DnaA box sequence CCGTTCACA abolished oriC activity in M. tuberculosis. Furthermore, by using a surface plasmon resonance technique we showed that purified M. tuberculosis DnaA protein binds native but not mutant DnaA box sequence, suggesting that stable interactions of the DnaA protein with the CCGTTCACA DnaA box are crucial for replication of oriC plasmids in vivo. Replacement by homologous recombination of the CCGTTCACA DnaA box sequence of the laboratory strain M. tuberculosis H37Ra with a mutant sequence did not result in nonviability. Together, these results suggest that M. tuberculosis strains have evolved mechanisms to tolerate mutations in the oriC region and that functional requirements for M. tuberculosis oriC replication are different for chromosomes and plasmids.

This article has been cited by other articles:

• Sernova, N. V., Gelfand, M. S. (2008). Identification of replication origins in prokaryotic genomes. Brief Bioinform 0: bbn031v1-bbn031 [Abstract] [Full Text]  
• Salazar, L., Guerrero, E., Casart, Y., Turcios, L., Bartoli, F. (2003). Transcription analysis of the dnaA gene and oriC region of the chromosome of Mycobacterium smegmatis and Mycobacterium bovis BCG, and its regulation by the DnaA protein. Microbiology 149: 773-784 [Abstract] [Full Text]  
• Greendyke, R., Rajagopalan, M., Parish, T., Madiraju, M. V. V. S. (2002). Conditional expression of Mycobacterium smegmatis dnaA, an essential DNA replication gene. Microbiology 148: 3887-3900 [Abstract] [Full Text]