Interaction studies on proteins encoded by the phthiocerol dimycocerosate locus of Mycobacterium tuberculosis

Mol Genet Genomics. 2004 Dec;272(5):571-9. doi: 10.1007/s00438-004-1088-3. Epub 2004 Nov 20.


Polyketide synthases (PKSs) of Mycobacterium tuberculosis are increasingly being seen as producers of virulence factors that are important for pathogenesis by the bacterium. Thus, the phenolphthiocerol synthase PKS cluster of M. tuberculosis is responsible, in part, for the synthesis of a virulence determinant called phthiocerol dimycocerosate (PDIM). Here, we provide evidence that the PpsE protein, which is part of that cluster, interacts with the type II thioesterase TesA of M. tuberculosis. The interaction was demonstrated by employing a two-hybrid system, and confirmed using a GST (glutathione S-transferase) pull-down' assay after both proteins had been purified to homogeneity. Based on the present findings, a revised model for the processing of polyketides during the synthesis of PDIM is presented.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbenicillin
  • DNA Primers
  • Fungal Proteins / metabolism
  • Glutathione Transferase
  • Lipid Metabolism*
  • Lipids / biosynthesis
  • Lipids / genetics
  • Models, Biological*
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / metabolism*
  • Mycobacterium tuberculosis / pathogenicity
  • Plasmids / genetics
  • Polyketide Synthases / metabolism*
  • Thiolester Hydrolases / metabolism
  • Two-Hybrid System Techniques
  • Virulence Factors / metabolism*


  • DNA Primers
  • Fungal Proteins
  • Lipids
  • Virulence Factors
  • phthiocerol dimycocerosate
  • Polyketide Synthases
  • Glutathione Transferase
  • Thiolester Hydrolases
  • Carbenicillin