Biochemists at Caltech have identified how viruses have converged on a method for killing bacteria. The researchers have homed in on an underexplored small transporter called MurJ that is a vital part of the pathway bacteria use to build their chain-mail-like cell wall. An essential component of the cell wall, called peptidoglycan, provides the strength that allows bacteria to resist pressure. Using advanced tools, the scientists have determined the common mechanism used by three different bacteria-killing viruses to block MurJ from doing its job. The findings reveal a novel target for designing new antibiotics.