Thinking outside the O sp( G )—kinase activation by E 2‐ubiquitin

Osp G is a secreted effector kinase from the human pathogen S higella that is required for the reduction of immune responses during S higella infection. A new study in The EMBO Journal provides a co‐crystal structure of O sp G bound to U bc H 5c~ U b, revealing how a bacterial kinase can be activated by the host ubiquitin conjugation machinery. These results provide molecular insight into an enigmatic microbial virulence factor that thwarts the host immune surveillance system to cause disease.