The structure of PknB in complex with mitoxantrone, an ATP-competitive inhibitor, suggests a mode of protein kinase regulation in mycobacteria

FEBS Lett. 2006 May 29;580(13):3018-22. doi: 10.1016/j.febslet.2006.04.046. Epub 2006 Apr 27.


Mycobacterium tuberculosis PknB is an essential receptor-like protein kinase involved in cell growth control. Here, we demonstrate that mitoxantrone, an anthraquinone derivative used in cancer therapy, is a PknB inhibitor capable of preventing mycobacterial growth. The structure of the complex reveals that mitoxantrone partially occupies the adenine-binding pocket in PknB, providing a framework for the design of compounds with potential therapeutic applications. PknB crystallizes as a 'back-to-back' homodimer identical to those observed in other structures of PknB in complex with ATP analogs. This organization resembles that of the RNA-dependent protein kinase PKR, suggesting a mechanism for kinase activation in mycobacteria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / antagonists & inhibitors
  • Dimerization
  • Mitoxantrone / chemistry*
  • Mitoxantrone / pharmacology
  • Mycobacterium tuberculosis / drug effects*
  • Mycobacterium tuberculosis / enzymology*
  • Protein Conformation
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein-Serine-Threonine Kinases / chemistry*
  • Protein-Serine-Threonine Kinases / metabolism


  • Adenosine Triphosphate
  • Mitoxantrone
  • PknB protein, Mycobacterium tuberculosis
  • Protein-Serine-Threonine Kinases