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08:05
Assaying Protein Kinase Activity with Radiolabeled ATP
Published on: May 26, 2017
Docking interactions induce exposure of activation loop in the MAP kinase ERK2
Tianjun Zhou1, Liguang Sun, John Humphreys
1Department of Biochemistry, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390, USA.
Structure (London, England : 1993)
|June 13, 2006
Summary
MAP kinases like ERK2 bind regulatory peptides via docking interactions. This study reveals how these interactions cause significant conformational changes, exposing key sites and enabling regulation.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Mitogen-activated protein (MAP) kinases regulate cellular processes through interactions with kinases, phosphatases, and substrates.
- Docking interactions are crucial for the specificity and regulation of MAP kinase activity.
Purpose of the Study:
- To elucidate the structural basis of MAP kinase regulation by docking peptides.
- To analyze the conformational changes induced by D-motif peptide binding to inactive ERK2.
Main Methods:
- X-ray crystallography at 1.9 Å resolution.
- Analysis of complexes between inactive ERK2 and D-motif peptides (pepHePTP and pepMEK2).
Main Results:
- Detailed structure of inactive ERK2 bound to a D-motif peptide (pepHePTP) from hematopoietic tyrosine phosphatase.
- Observed extensive electrostatic interactions at the "CD" site and significant conformational changes in the activation loop.
- Dual phosphorylation sites in ERK2 become solvent-exposed upon peptide binding.
- Similar conformational changes were induced by a MEK2-derived D-motif peptide (pepMEK2).
Conclusions:
- D-motif peptides induce unique conformational changes in MAP kinases, contributing to enzyme specificity.
- The binding and subsequent structural rearrangements are critical for the regulation of MAP kinase activity by phosphatases and kinases.
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