It's the first time the argonaute protein has been seen bound to both target and guide strands.Science A picture of a bacterial protein complex that selects and slices up RNA molecules, thereby silencing genes, provides fresh insight into the process of RNA interference (RNAi), researchers say. The structure is the first to capture the so-called argonaute protein when it is bound to both the genetic template that guides it to its RNA target, and the target strand of RNA itself.Researchers use RNAi to block expression of selected genes, and some hope that it can be used to fight diseases....