TP0262 is a modulator of promoter activity of tpr Subfamily II genes of Treponema pallidum ssp. pallidum

Mol Microbiol. 2009 Jun;72(5):1087-99. doi: 10.1111/j.1365-2958.2009.06712.x. Epub 2009 Apr 30.

Abstract

Transcriptional regulation in Treponema pallidum ssp. pallidum is poorly understood, primarily because this organism cannot be cultivated in vitro or genetically manipulated. We have recently shown a phase variation mechanism controlling transcription initiation of Subfamily II tpr (T. pallidumrepeat) genes (tprE, tprG and tprJ), a group of virulence factor candidates. Furthermore, the same study suggested that additional mechanisms might influence the level of transcription of these tprs. The T. pallidum genome sequence has revealed a few open reading frames with similarity to known bacterial transcription factors, including four catabolite activator protein homologues. In this work, sequences matching the Escherichia coli cAMP receptor protein (CRP) binding motif were identified in silico upstream of tprE, tprG and tprJ. Using elecrophoretic mobility shift assay and DNaseI footprinting assay, recombinant TP0262, a T. pallidum CRP homologue, was shown to bind specifically to amplicons obtained from the tpr promoters containing putative CRP binding motifs. Using a heterologous reporter system, binding of TP0262 to these promoters was shown to either increase (tprE and tprJ) or decrease (tprG) tpr promoter activity. This is the first characterization of a T. pallidum transcriptional modulator that influences tpr promoter activity.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Cloning, Molecular
  • Cyclic AMP Receptor Protein / genetics*
  • Cyclic AMP Receptor Protein / metabolism
  • DNA Footprinting
  • DNA, Bacterial / genetics
  • Electrophoretic Mobility Shift Assay
  • Escherichia coli / genetics
  • Gene Expression Regulation, Bacterial
  • Molecular Sequence Data
  • Promoter Regions, Genetic*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Transcription, Genetic
  • Treponema pallidum / genetics*
  • Treponema pallidum / metabolism

Substances

  • Bacterial Proteins
  • Cyclic AMP Receptor Protein
  • DNA, Bacterial
  • Recombinant Proteins