The COVID-19 disease caused by the SARS-CoV-2 coronavirus has become a pandemic health crisis. An attractive target for antiviral inhibitors is the main protease 3CL Mpro due to its essential role in processing the polyproteins translated from viral RNA. The Crystallization Center worked with samples from Oak Ridge National Laboratory to help a study on room temperature X-ray structure of unliganded SARS-CoV-2 3CL Mpro. Inital crystal hits helped the researchers determine the ligand-free structure of the active site and the conformation of the catalytic site cavity at near-physiological temperature. They note comparison with previously reported low-temperature ligand-free and inhibitor-bound structures suggest that the room temperature structure may provide more relevant information at physiological temperatures for aiding in molecular docking studies. Structural plasticity of SARS-CoV-2 3CL Mpro active site cavity revealed by room temperature X-ray crystallography Kneller, DW, et al Nat Commun 11, 3202 (2020).