Real-time investigation of dynamic protein crystallization in living cells.

X-ray crystallography requires sufficiently large crystals to obtain structural insights at atomic resolution, routinely obtained in vitro by time-consuming screening. Recently, successful data collection was reported from protein microcrystals grown within living cells using highly brilliant free-electron laser and thirdgeneration synchrotron radiation. Here, we analyzed in vivo crystal growth of firefly luciferase and Green Fluorescent Protein-tagged reovirus mu NS by live-cell imaging, showing that dimensions of living cells did not limit crystal size. The crystallization process is highly dynamic and occurs in different cellular compartments. In vivo protein crystallization offers exciting new possibilities for proteins that do not form crystals in vitro. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.