Clues from Crystals (image) American Institute of Physics Caption The functions of novel proteins putatively involved in F. tularensis virulence are revealed by X-ray crystallography. Credit LLNL/G. K. Feld/CDC Usage Restrictions The image may be used only with appropriate caption and credit. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.