ERK2: Comparison of phoshorylated  and non phosphorylated forms

Extracellular regulated kinase 2 (ERK2), also known as mitogen activate protein kinase 2 (MAPK2) is a protein the plays a vital role in cell signaling across the cell membrane. Phosphoryation of ERK2 on Threonine 183 (Thr153) and Tyrosine 185 (Tyr185) leads to a structural change in the protein.

ERK2 -  unphosphorylated, line drawing with Thr183 and Tyr185 in space fill rendering (1ERK.pdb)

ERK2- unphosphosphorylated, backbone trace with Thr183 and Tyr185 side chains rendered in spacefill. The orientation  of six positively charged Arg side chains (65, 68, 146, 170, 189 and 192) are also shown.  Note especially that Thr 183 is not near any of the Arg side chains.

ERK2 -  phosphorylated, backbone trace with pT183 and pY185 in space fill rendering (2ERK.pdb)

ERK2 -  phosphorylated, backbone trace with pThr183 interacting with Arg 65, 68, 146, and 170 and pTyr185 interacting with Arg 189 and Arg 192. Note that in the unphosphorylated form, Thr 183 is not near any of the Arg side chains.

Comparison of unphosphorylated (black) and phosphorylated (magenta) backbone trace

Comparison of backbone trace of amino acids 176-206 and translucent spacefill rendering of Thr 183/Tyr 185 side chains in  unphosphorylated ERK2 (black) with the same amino acids and spacefill rendering of pThr 183/pTyr side chains in phosphorylated (magenta) ERK2

Comparison of backbone trace of amino acids 60-190 with the Arg (65, 68, 146, and 170) cluster in spacefill.  Note the distance between Thr183 and the Arg cluster  in the unphosphorylated form and between pThr183 and the cluster in the phosphorylated form.  Phosophorylation is accompanied by a movement of pThr183 which is negatively charged towards the positively charged Arg cluster.  The Arg side chains in the cluster don't move significantly on phosphorylation.