Abstract
Purpose:
Olfactomedin (OLF) domains comprise a large family of proteins found throughout the body, predominantly within extracellular multidomain proteins, that are involved in aspects of development. Even though they have been implicated in a range of disorders, most prominently glaucoma, but also cancers, childhood obesity, inflammatory bowel disease, and attention deficit disorder, little is known about their structure and specific biological function. The purpose of the study was to crystallize and solve the molecular structures of OLF domains from different phylogenetic subfamilies.
Methods:
Recombinant expression and purification of OLF domains, their crystallization, X-ray diffraction data collection, structure solution, model building, and refinement.
Results:
Crystal structures of three different OLFs were each solved to ~2 Å resolution, revealing the overall architecture and precise location of every amino acid in the domain, as well as surface charges, hydrophilic channels, calcium, and location of other ions.
Conclusions:
The structures significantly expand our appreciation of the physicochemical diversity of the OLF domain, and support a biological function involving protein-protein or protein-ligand interactions common to the broader propeller structural class.