Structural studies on CLIMP-63

CLIMP-63 (cytoskeleton-linking membrane protein 63) is a key player in the formation of the correct endoplasmic reticulum (ER) structure. It has been shown that in the ER, CLIMP-63 assembles into trimeric units and higher order super-stable structures that are S-acylated. We have expressed and purified several truncated constructs of CLIMP-63 from several species that lack the transmembrane domain. This soluble ER luminal domain (monomer mass ~58kDa) behaves as a trimer in vitro (shown by MALS and mass photometry analysis), most likely forming a parallel coiled-coil. While crystallisation experiments are set up, we would like to study the conformation of these CLIMP-63 variants in solution using SEC-SAXS. Structural information obtained by SAXS, in combination with our biophysical studies, would be very useful to validate the 3D models and assess the sample heterogeneity and suitability to perform further crystallographic and cryo-EM experiments.