Serine/threonine protein kinases PknF and PknG of Mycobacterium tuberculosis: Characterization and localization

A. Koul, A. Choidas, A. K. Tyagi, K. Drlica, Y. Singh, A. Ullrich

Research output: Contribution to journalArticlepeer-review

90 Scopus citations


Pathogenesis of Mycobacterium tuberculosis is closely connected to its survival and replication within the host. Some pathogenic bacteria employ protein kinases that interfere with the cellular signalling network of host cells and promote bacterial survival. In this study, the pknF and pknG genes, which encode two putative protein kinases of M. tuberculosis H37Rv, protein kinase F (PknF) and protein kinase G (PknG), respectively, were cloned and expressed in Escherichia coli. Purified PknF phosphorylated the peptide substrate myelin basic protein (MBP) at serine and threonine residues, while purified PknG phosphorylated only at serine residues. The activity of the two kinases was abrogated by mutation of the codon for the predicted ATP-binding-site lysine residue. Southern blot analysis revealed that homologues of the genes encoding the two kinases are present in M. tuberculosis H37Ra and Mycobacterium bovis BCG, but not in Mycobacterium smegmatis. Immunoblot analysis of various cellular fractions of M. tuberculosis H37Rv revealed that PknF is a transmembrane protein and that PknG is predominantly a cytosolic enzyme. The present study should aid in elucidating the role of these protein kinases in the pathogenesis of mycobacteria.

Original languageEnglish (US)
Pages (from-to)2307-2314
Number of pages8
Issue number8
StatePublished - 2001
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Microbiology


  • Glutathione S-transferase
  • Mycobacteria
  • Protein phosphorylation
  • Transmembrane
  • Tuberculosis


Dive into the research topics of 'Serine/threonine protein kinases PknF and PknG of Mycobacterium tuberculosis: Characterization and localization'. Together they form a unique fingerprint.

Cite this