Structural basis for misfolding in myocilin-associated glaucoma.

Area of Science:

• Structural biology
• Molecular genetics
• Ophthalmology

Background:

• Olfactomedin (OLF) domain proteins are crucial for cellular functions and linked to various diseases.
• Mutations in myocilin's OLF domain (myoc-OLF) cause inherited glaucoma.
• The OLF domain family has diverse roles, but specific functions remain elusive.

Purpose of the Study:

• To determine the crystal structure of the myocilin OLF domain (myoc-OLF).
• To identify structural features relevant to glaucoma pathogenesis.
• To analyze evolutionary conservation within the OLF domain family.

Main Methods:

• X-ray crystallography to solve the myoc-OLF structure.
• Mapping of glaucoma-associated mutations onto the structure.
• Comparative evolutionary analysis of OLF domains.

Main Results:

• The myoc-OLF structure reveals a novel five-bladed beta-propeller fold.
• A central cavity contains calcium, sodium, and glycerol, accessible via loop movements.
• Three aggregation-sensitive regions were identified, aiding mutation classification.
• Evolutionary analysis highlights conserved and divergent regions for protein interactions.

Conclusions:

• Atomic-level structural knowledge of myoc-OLF provides a framework for understanding glaucoma mutations.
• The findings facilitate differentiation between neutral and pathogenic mutations.
• Structural insights guide future research into the broader OLF domain family's functions.