Common themes in kinases

Serine/threonine (Ser/Thr) protein kinases catalyze the phosphoryl transfer reaction from a phosphate donor (usually ATP) to a receptor substrate. Kinases that resemble eukaryotic Ser/Thr kinases have also been identified in several bacteria, including Mycobacterium tuberculosis, and are potential antimycobacterial targets. But little is known about their structures and mechanisms of activation. In the January 27 online Nature Structural Biology, Tracy A. Young and colleagues from University of California, Berkeley, USA, show that the structure of Mycobacterium tuberculosis PknB kinase supports a universal activation mechanism for Ser/Thr protein kinases.

Young et al. observed that the M. tuberculosis PknB kinase domain is active autonomously, and that the active enzyme is phosphorylated on residues homologous to the regulatory phospho-acceptors in eukaryotic Ser/Thr kinases. In addition, they showed that the crystal structure of the PknB kinase domain in complex with an ATP analog is similar to that of activated eukaryotic...