SARS enzyme finding could help advance MERS vaccine

In an important step toward the creation of a vaccine against deadly coronaviruses, researchers from Purdue University have figured out how to disable a key enzyme of the SARS virus that helps it trick the immune system. The investigators have captured the molecular structure of this SARS enzyme–called a papain-like protease, or PLpro–showing how it strips a host cell of two proteins, ubiquitin and ISG15, that are involved in triggering an immune response. PLpro also plays a major role in viral replication because of its ability to clip viral polyproteins into individual proteins. Snipping these proteins effectively prevents the host cell from alerting the immune system to the presence of the virus, allowing it to further infect cells. The findings, which were published in PLOS Pathogens, could help scientists develop a vaccine against severe acute respiratory syndrome (SARS), and its harder-to-transmit but more lethal relative, Middle East respiratory syndrome coronavirus (MERS). Currently, there...