Structural studies of P-type ATPase–ligand complexes using an X-ray free-electron laser
Category
Published on
Type
journal-article
Author
Maike Bublitz and Karol Nass and Nikolaj D. Drachmann and Anders J. Markvardsen and Matthias J. Gutmann and Thomas R. M. Barends and Daniel Mattle and Robert L. Shoeman and R. Bruce Doak and Sébastien Boutet and Marc Messerschmidt and Marvin M. Seibert and Garth J. Williams and Lutz Foucar and Linda Reinhard and Oleg Sitsel and Jonas L. Gregersen and Johannes D. Clausen and Thomas Boesen and Kamil Gotfryd and Kai-Tuo Wang and Claus Olesen and Jesper V. Møller and Poul Nissen and Ilme Schlichting
Citation
Bublitz, M. et al., 2015. Structural studies of P-type ATPase–ligand complexes using an X-ray free-electron laser. IUCrJ, 2(4), pp.409–420. Available at: http://dx.doi.org/10.1107/s2052252515008969.
Abstract
Membrane proteins are key players in biological systems, mediating signalling events and the specific transport ofe.g.ions and metabolites. Consequently, membrane proteins are targeted by a large number of currently approved drugs. Understanding their functions and molecular mechanisms is greatly dependent on structural information, not least on complexes with functionally or medically important ligands. Structure determination, however, is hampered by the difficulty of obtaining well diffracting, macroscopic crystals. Here, the feasibility of X-ray free-electron-laser-based serial femtosecond crystallography (SFX) for the structure determination of membrane protein–ligand complexes using microcrystals of various native-source and recombinant P-type ATPase complexes is demonstrated. The data reveal the binding sites of a variety of ligands, including lipids and inhibitors such as the hallmark P-type ATPase inhibitor orthovanadate. By analyzing the resolution dependence of ligand densities and overall model qualities, SFX data quality metrics as well as suitable refinement procedures are discussed. Even at relatively low resolution and multiplicity, the identification of ligands can be demonstrated. This makes SFX a useful tool for ligand screening and thus for unravelling the molecular mechanisms of biologically active proteins.
DOI
Funding
NSF-STC Biology with X-ray Lasers (NSF-1231306)