TetX2 (IMAGE) Rice University Caption Researchers examined the structure and performance of seven forms of a protein called TetX2 that had evolved to allow E. coli to resist attacks by the antibiotic minocycline. This image shows how a molecule of the drug, shown in yellow and gray, fits within the active site of a TetX2 protein. Credit Y. Shamoo/Rice University Usage Restrictions Must credit: License Licensed content 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.