Significant advances have recently been made in understanding the regulation of Ca2+-ATPase by phospholamban and in modeling their structures. However, these insights would be furthered by determining the 3-D structure of both proteins within the membrane, thus revealing the structural basis for their interaction. To this end, we have developed methods for reconstituting purified Ca2+-ATPase with recombinant phospholamban. After reconstitution at high lipid-to-protein ratios, we have verified their functional association by measuring calcium transport and ATPase activity. Furthermore, we have grown co-crystals after reconstitution at low lipid-to-protein ratios. The structure of Ca2+-ATPase has recently been solved by cryoelectron microscopy at 8-Å resolution, thus revealing transmembrane α-helices. Using a variety of constraints, we have associated these helices with the predicted transmembrane sequences to produce a detailed model for the packing of transmembrane helices. Structure determination of the co-crystals is currently underway, which we hope will eventually reveal the interaction of phospholamban with Ca2+-ATPase at a similar level of detail.
|Original language||English (US)|
|Number of pages||13|
|Journal||Annals of the New York Academy of Sciences|
|State||Published - Jan 1 1998|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- History and Philosophy of Science