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Updated: Jun 6, 2026

Identification of Post-translational Modifications of Plant Protein Complexes
Published on: February 22, 2014
The third conformation of p38α MAP kinase observed in phosphorylated p38α and in solution
Radha Akella1, Xiaoshan Min, Qiong Wu
1Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390-8816, USA.
Abstract:
MAPKs engage substrates, MAP2Ks, and phosphatases via a docking groove in the C-terminal domain of the kinase. Prior crystallographic studies on the unphosphorylated MAPKs p38α and ERK2 defined the docking groove and revealed long-range conformational changes affecting the activation loop and active site of the kinase induced by peptide. Solution NMR data presented here for unphosphorylated p38α with a MEK3b-derived peptide (p38α/pepMEK3b) validate these findings. Crystallograhic data from doubly phosphorylated active p38α (p38α/T∗GY∗/pepMEK3b) reveal a structure similar to unphosphorylated p38α/MEK3b, and distinct from phosphorylated p38γ (p38γ/T∗GY∗) and ERK2 (ERK2/T∗EY∗). The structure supports the idea that MAP kinases adopt three distinct conformations: unphosphorylated, phosphorylated, and a docking peptide-induced form.
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