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

Unité de Biochimie Structurale and CNRS URA2185, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris, France.
FEBS Letters (Impact Factor: 3.34). 06/2006; 580(13):3018-22. DOI: 10.1016/j.febslet.2006.04.046
Source: PubMed

ABSTRACT 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.

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