Structure of the LKB1-STRAD-MO25 Complex Reveals an Allosteric Mechanism of Kinase Activation

Solving Pseudokinases Mutations of the protein kinase LKB1 are associated with cancer in humans. Many kinases are activated by phosphorylation, but LKB1 is activated by STRADα, a pseudokinase that is similar to protein kinases and binds ATP, but does not phosphorylate substrates. By solving the crystal structure of an activating complex containing LKB, Zeqiraj et al. (p. 1707 , published online 5 November) show that STRADα works with another protein, MO25α, to hold LKB1 in an active conformation. The results may help explain the evolutionary origin of pseudokinases, the biological roles of other pseudokinases, and the mechanisms of disease-causing mutations in LKB1.