@article {Keedy016733, author = {Daniel A. Keedy and Lillian R. Kenner and Matthew Warkentin and Rahel A. Woldeyes and Michael C. Thompson and Aaron S. Brewster and Andrew H. Van Benschoten and Elizabeth L. Baxter and Jesse B. Hopkins and Monarin Uervirojnangkoorn and Scott E. McPhillps and Jinhu Song and Roberto Alonso-Mori and James M. Holton and William I. Weis and Axel T. Brunger and S. Michael Soltis and Henrik Lemke and Ana Gonzalez and Nicholas K. Sauter and Aina E. Cohen and Henry van den Bedem and Robert E. Thorne and James Fraser}, title = {Mapping the Conformational Landscape of a Dynamic Enzyme by XFEL and Multitemperature Crystallography}, elocation-id = {016733}, year = {2015}, doi = {10.1101/016733}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Determining the interconverting conformations of dynamic proteins in atomic detail is a major challenge for structural biology. Conformational heterogeneity in the active site of the dynamic enzyme cyclophilin A (CypA) has been previously linked to its catalytic function. Here we compare the conformational ensembles of CypA by fixed-target X-ray free electron laser (XFEL) crystallography and multitemperature synchrotron crystallography. The {\textquotedblleft}diffraction-before-destruction{\textquotedblright} nature of XFEL experiments provides a radiation-damage-free view of the functionally important alternative conformations of CypA. We monitored the temperature dependences of these alternative conformations with eight synchrotron datasets spanning 100-310 K. Multiconformer models show that many alternative conformations in CypA are populated above, but not below, the glass transition temperature (\~{}200 K) and reveal abrupt changes in protein flexibility that provide all-atom insight into conformational coupling. Together, our XFEL data and multitemperature analyses motivate a new generation of time-resolved experiments to structurally characterize the dynamic underpinnings of protein function.}, URL = {https://www.biorxiv.org/content/early/2015/03/19/016733}, eprint = {https://www.biorxiv.org/content/early/2015/03/19/016733.full.pdf}, journal = {bioRxiv} }