Deep mutational scanning reveals the structural basis for α-synuclein activity.

Area of Science:

• Biochemistry
• Structural Biology
• Molecular Biology

Background:

• Determining protein structures in cellular environments is difficult, especially for proteins with multiple functional conformations.
• Alpha-synuclein (α-synuclein) is a protein known for its disordered, helical, and amyloid forms.

Purpose of the Study:

• To investigate the structure and dynamics of α-synuclein within a cellular context.
• To identify the specific conformation of α-synuclein responsible for its biological activity.

Main Methods:

• Utilized deep mutational scanning on 2,600 single-residue substitutions of α-synuclein.
• Assessed the impact of these mutations on the protein's ability to inhibit yeast growth.

Main Results:

• Identified a long, uninterrupted, amphipathic helix as the biologically active conformation of α-synuclein.
• Observed increased dynamics towards the C-terminus of this helical structure.

Conclusions:

• Deep mutational scanning is effective for determining biologically active protein conformations in vivo.
• This technique can resolve structures of highly dynamic, multi-conformational proteins like α-synuclein.