An M. tuberculosis DNA fragment contains genes encoding cell division proteins ftsX and ftsE, a basic protein and homologues of PemK and small protein B.
A 4-kb fragment of the M. tuberculosis chromosome was identified which contains several genes including those involved in cell division and possibly macrophage survival. DNA sequence analysis revealed open reading frames (ORFs) encoding putative proteins bearing significant homology with proteins FtsX and FtsE associated with cell division in E. coli, with PemK protein which inhibits cell division in E. coli harboring plasmid R100 and with SmpB protein of Salmonella typhimurium implicated in its survival within macrophages. The ftsX gene is conserved among mycobacteria belonging to the M. tuberculosis Complex. Furthermore, ftsX-specific transcripts were prevalent in equivalent amounts in M. tuberculosis H37Rv and H37Ra as analyzed by RT-PCR and primer extension. Transcription start points (tsp) a and b map in the region upstream of the FtsX ORF whose promoter activity was established by (i) a promoter-fusion experiment and (ii) by mapping the 5' ends of transcripts derived from the promoter-fusion construct. FtsX transcription is modulated as a function of mycobacterial growth and division status, maximum expression being observed in log phase cells. Growth-related expression of ftsX may provide a basis for developing a marker to distinguish actively replicating M. tuberculosis cells from quiescent mycobacteria.
Tyagi
J S
JS
Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India. ist@aiims.ernet.in
Das
T K
TK
Kinger
A K
AK
D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D018797:Cell Cycle Proteins / Q000235:genetics*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D004269:DNA, Bacterial; D004279:DNA, Viral; D004268:DNA-Binding Proteins / Q000235:genetics*; D029968:Escherichia coli Proteins; D015870:Gene Expression; D005819:Genetic Markers; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000254:growth & development; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D017386:Sequence Homology, Amino Acid
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D004269:DNA, Bacterial; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C491157:FtsX protein, E coli; C102286:FtsX protein, bacteria; D005819:Genetic Markers; C080273:PemK protein, E coli; C075980:FtsE protein, E coli; D019005:Cystic Fibrosis Transmembrane Conductance Regulator