Competition between Coiled-Coil Structures and the Impact on Myosin-10 Bundle Selection.

Area of Science:

• Protein engineering
• Structural biology
• Biophysics

Background:

• Coiled-coil fusions are used to enforce protein dimerization.
• The final structures of these fusion proteins are not well understood.
• Myosin-10 stabilization in biophysical studies relies on coiled coils.

Purpose of the Study:

• To determine the structural outcome of adjacent parallel and antiparallel coiled coils.
• To investigate the structure of myosin-10 coiled coils fused to GCN4-p1.
• To understand the implications for myosin-10 function.

Main Methods:

• Solution structure determination using biophysical techniques.
• Analysis of coiled-coil fusion protein structures.
• Investigating protein dynamics and folding cooperativity.

Main Results:

• A short, antiparallel myosin-10 coiled coil fused to a parallel GCN4-p1 coiled coil formed a continuous antiparallel coiled coil.
• GCN4-p1 unexpectedly paired with myosin-10, not itself.
• Longer myosin-10 segments in fusions were dynamic and did not fold cooperatively.

Conclusions:

• The orientation and stability of coiled coils significantly impact fusion protein structure.
• These findings resolve conflicting data regarding myosin-10's interaction with actin filament bundles.
• Understanding coiled-coil architecture is essential for protein engineering and biophysical applications.