RT Journal Article SR Electronic T1 Mapping the Conformational Landscape of a Dynamic Enzyme by XFEL and Multitemperature Crystallography JF bioRxiv FD Cold Spring Harbor Laboratory SP 016733 DO 10.1101/016733 A1 Daniel A. Keedy A1 Lillian R. Kenner A1 Matthew Warkentin A1 Rahel A. Woldeyes A1 Michael C. Thompson A1 Aaron S. Brewster A1 Andrew H. Van Benschoten A1 Elizabeth L. Baxter A1 Jesse B. Hopkins A1 Monarin Uervirojnangkoorn A1 Scott E. McPhillps A1 Jinhu Song A1 Roberto Alonso-Mori A1 James M. Holton A1 William I. Weis A1 Axel T. Brunger A1 S. Michael Soltis A1 Henrik Lemke A1 Ana Gonzalez A1 Nicholas K. Sauter A1 Aina E. Cohen A1 Henry van den Bedem A1 Robert E. Thorne A1 James Fraser YR 2015 UL http://biorxiv.org/content/early/2015/03/19/016733.abstract AB 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 “diffraction-before-destruction” 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.