Title :
Olfactomedin-1 Has a V-shaped Has a V-shaped Disulfide-linked Tetrameric Structure
Abstract :
- Olfactomedin-1 ( Olfm1 ; also known as noelin and pancortin) is a member of the olfactomedin domain-containing superfamily and a highly expressed neuronal glycoprotein important for nervous system development
- It binds a number of secreted proteins and cell surface-bound receptors to induce cell signaling processes
- Using a combined approach of x-ray crystallography, solution scattering, analytical ultracentrifugation, and electron microscopy we determined that full-length Olfm1 forms disulfide-linked tetramers with a distinctive V-shaped architecture
- The base of the "V" is formed by two disulfide-linked dimeric N-terminal domains
- Each of the two V legs consists of a parallel dimeric disulfide-linked coiled coil with a C-terminal β-propeller dimer at the tips
- This agrees with our crystal structure of a C-terminal coiled-coil segment and β-propeller combination ( Olfm1 ( coil-Olf )) that reveals a disulfide-linked dimeric arrangement with the β-propeller top faces in an outward exposed orientation
- Similar to its family member myocilin , Olfm1 is stabilized by calcium
- The dimer-of-dimers architecture suggests a role for Olfm1 in clustering receptors to regulate signaling and sheds light on the conformation of several other olfactomedin domain family members