Researchers at the European Molecular Biology Laboratory (EMBL) in Grenoble, France, have determined the detailed 3-dimensional structure of an enzyme called endonuclease (a part of the viral RNA polymerase) which is responsible for a unique mechanism that allows the virus to trick its host cell into producing viral proteins. This important finding is published on the 2nd of August issue of PLoS Pathogens 8:1-14 under the title, “Structural Analysis of Specific Metal Chelating Inhibitor Binding to the Endonuclease Domain of Influenza pH1N1 (2009) Polymerase”. The researchers were capable to visualize the process of several different small molecule inhibitors that bind and block its active site. The active site of the endonuclease is shaped like a cave with two metal ions at the bottom. It was demonstrated that all the studied inhibitors bind to those metal ions but different inhibitors (depending on their shapes) bind differently to the amino-acids of the cave’s walls. Based on this detailed structural information it is now possible to design new synthetic chemicals which bind even more tightly to the endonuclease active site and thus will potentially be more potent inhibitors of influenza virus replication. [Summarized by the graduate student, Samsad Razzaque.]