+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

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



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(Pt 3): 773-784



The regions flanking the Mycobacterium dnaA gene have extensive sequence conservation, and comprise various DnaA boxes. Comparative analysis of the dnaA promoter and oriC region from several mycobacterial species revealed that the localization, spacing and orientation of the DnaA boxes are conserved. Detailed transcriptional analysis in M. smegmatis and M. bovis BCG shows that the dnaN gene of both species and the dnaA gene of M. bovis BCG are transcribed from two promoters, whereas the dnaA gene of M. smegmatis is transcribed from a single promoter. RT-PCR with total RNA showed that dnaA and dnaN were expressed in both species at all growth stages. Analysis of the promoter activity using dnaA-gfp fusion plasmids and DnaA expression plasmids indicates that the dnaA gene is autoregulated, although the degree of transcriptional autorepression was moderate. Transcription was also detected in the vicinity of oriC of M. bovis BCG, but not of M. smegmatis. These results suggest that a more complex transcriptional mechanism may be involved in the slow-growing mycobacteria, which regulates the expression of dnaA and initiation of chromosomal DNA replication.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 003991509

Download citation: RISBibTeXText

PMID: 12634345

DOI: 10.1099/mic.0.25832-0


Related references

Titration of DnaA protein by oriC DnaA-boxes increases dnaA gene expression in Escherichia coli. Embo Journal 6(1): 255-258, 1987

The intrinsic ATPase activity of Mycobacterium tuberculosis DnaA promotes rapid oligomerization of DnaA on oriC. Molecular Microbiology 59(6): 1876-1890, 2006

Mutations in the CCGTTCACA DnaA box of Mycobacterium tuberculosis oriC that abolish replication of oriC plasmids are tolerated on the chromosome. Journal of Bacteriology 184(14): 3848-3855, 2002

Inhibition of chromosome replication in Mycobacterium smegmatis: effect of the rpmH-dnaA promoter region. Microbiology 146: 2199-2207, 2000

Replacement of Mycobacterium smegmatis dnaA gene by Mycobacterium tuberculosis homolog results in temperature sensitivity. Tuberculosis 91(Suppl. 1): S136-S141, 2011

Mycobacterium smegmatis dnaA region and autonomous replication activity. Journal of Bacteriology 177(22): 6527-6535, 1995

Conditional expression of Mycobacterium smegmatis dnaA, an essential DNA replication gene. Microbiology 148(Pt 12): 3887-3900, 2002

Investigation of the oriC activities of plasmids containing IS6110 insertions in the DnaA-DnaN intergenic region derived from clinical strains of Mycobacterium tuberculosis. Abstracts of the General Meeting of the American Society for Microbiology 101: 712, 2001

Directionality of DnaA protein/Dna interaction. Active orientation of the DnaA protein/dnaA box complex in transcription termination. The Embo Journal 8(5): 1609-1613, 1989

Conserved hydrophobic amino acid residues in the N-terminal region of DnaA protein are involved in DnaA-DnaA interaction. Biochemical Journal 365(Pt 3): 881-887, 2002

DnaA protein binding to individual DnaA boxes in the Escherichia coli replication origin, oriC. Embo Journal 16(21): 6574-6583, 1997

The presence of two DnaA-binding sequences is required for an efficient interaction of the Escherichia coli DnaA protein with each particular weak DnaA box region. FEMS Microbiology Letters 174(1): 25-31, 1999

Mutational analysis reveals Escherichia coli oriC interacts with both DnaA-ATP and DnaA-ADP during pre-RC assembly. Molecular Microbiology 66(2): 428-439, 2007

Mycobacterium tuberculosis DnaA-oriC interactions and a working model. 2005

Unique genetic arrangement in the dnaA region of the Borrelia burgdorferi linear chromosome: nucleotide sequence of the dnaA gene. Fems Microbiology Letters 111(1): 109-114, 1993