The structures of the kinase domain and UBA domain of MPK38 suggest the activation mechanism for kinase activity

The structure of a crystal of MPK38 (T167E), which consists of a kinase domain and a UBA domain, in complex with AMP-PNP is reported at 2.4 Å resolution. The structure indicates that the activation of MPK38 is induced by the UBA linker restraining the motion of the αC helix and by phosphorylation of Thr167 stabilizing the activation loop.