A virally encoded tRNA neutralizes the PARIS antiviral defence system.

ABSTRACT: Viruses compete with each other for limited cellular resources, and some deliver defence mechanisms that protect the host from competing genetic parasites¹. The phage antirestriction induced system (PARIS) is a defence system, often encoded in viral genomes, that is composed of a 55 kDa ABC ATPase (AriA) and a 35 kDa TOPRIM nuclease (AriB)². However, the mechanism by which AriA and AriB function in phage defence is unknown. Here we show that AriA and AriB assemble into a 425 kDa supramolecular immune complex. We use cryo-electron microscopy to determine the structure of this complex, thereby explaining how six molecules of AriA assemble into a propeller-shaped scaffold that coordinates three subunits of AriB. ATP-dependent detection of foreign proteins triggers the re

SUBMITTER: Burman N 

PROVIDER: S-EPMC11464382 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature