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Modeling an Enzyme Active Site using Molecular Visualization Freeware
Published on: December 25, 2021
A model of a MAPK•substrate complex in an active conformation: a computational and experimental approach
Sunbae Lee1, Mangalika Warthaka, Chunli Yan
1Division of Medicinal Chemistry, University of Texas at Austin, Austin, Texas, United States of America.
Plos One
|April 16, 2011
Summary
This study reveals how the unstructured N-terminus of Ets-1 stabilizes its interaction with ERK2, enhancing substrate phosphorylation. Introducing a consensus docking site significantly boosts kinase activity.
Area of Science:
- Molecular Biology
- Biochemistry
- Enzymology
Background:
- Mitogen-activated protein kinase (MAPK) substrate recognition and phosphorylation mechanisms remain incompletely understood.
- The lack of MAPK-substrate structures hinders mechanistic investigations.
- While MAPK-substrate docking is established, its role in promoting phosphorylation is unclear.
Purpose of the Study:
- To elucidate the molecular mechanisms of Ets-1 N-terminus association with ERK2.
- To investigate how this interaction influences substrate phosphorylation by ERK2.
- To explore the role of docking sites in MAPK-substrate complex stabilization.
Main Methods:
- Utilized computer modeling with experimental restraints to predict Ets-1 N-terminus and ERK2 interactions.
- Employed mutagenesis experiments guided by computational models.
- Performed kinetic analysis of wild-type and mutant Ets-1 phosphorylation by ERK2.
Main Results:
- The Ets-1 N-terminus lacks a canonical ERK2 docking site but stabilizes the complex while remaining disordered.
- Specific residues (Leu-11, Ile-13, Ile-14) in Ets-1 contribute to binding via ERK2's D-recruiting site (DRS).
- Introducing a consensus docking site increased catalytic efficiency (kcat/Km) twofold; deleting the N-terminus decreased it 14-fold.
Conclusions:
- The unstructured Ets-1 N-terminus uniformly stabilizes the ERK2-Ets-MgATP complex and reaction intermediates, contributing a 10-fold stabilization effect.
- Docking site engineering can enhance MAPK substrate phosphorylation efficiency.
- Understanding these interactions is crucial for deciphering MAPK signaling pathways.
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