Designed Mutations Alter the Binding Pathways of an Intrinsically Disordered Protein

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• Intrinsically disordered proteins (IDPs) are crucial for cellular signaling and regulation.
• IDPs bind targets through mechanisms that are increasingly understood via experimental and computational studies.
• A common mechanism involves IDPs becoming structured upon binding, following a 'dock-and-coalesce' pathway.

Purpose of the Study:

• To critically test the mechanistic understanding of the dominant dock-and-coalesce pathway in intrinsically disordered protein binding.
• To investigate how electrostatic attraction and molecular flexibility contribute to dominant pathway selection.
• To engineer mutations to specifically alter the dominant binding pathway of IDPs.

Main Methods:

• Computational modeling to predict and analyze IDP binding pathways.
• Site-directed mutagenesis to introduce specific alterations in IDPs.
• Biophysical techniques to characterize protein-target interactions and structural changes.

Main Results:

• Identified key residues and interactions governing the dominant dock-and-coalesce pathway.
• Demonstrated that specific mutations can indeed reroute the preferred binding pathway.
• Showcased the roles of electrostatic forces in initial docking and conformational flexibility in subsequent coalescence.

Conclusions:

• The dock-and-coalesce mechanism is a robust model for IDP-target binding.
• Precise manipulation of IDP binding pathways is achievable through targeted mutations.
• This work provides a foundation for controlling cellular functions mediated by IDPs.