Saikat Chowdhury / Joshua Carter / MaryClare F Rollins / Sarah M Golden / Ryan N Jackson / Connor Hoffmann / Lyn'Al Nosaka / Joseph Bondy-Denomy / Karen L Maxwell / Alan R Davidson / Elizabeth R Fischer / Gabriel C Lander / Blake Wiedenheft /
PubMed 要旨
Genetic conflict between viruses and their hosts drives evolution and genetic innovation. Prokaryotes evolved CRISPR-mediated adaptive immune systems for protection from viral infection, and viruses ...Genetic conflict between viruses and their hosts drives evolution and genetic innovation. Prokaryotes evolved CRISPR-mediated adaptive immune systems for protection from viral infection, and viruses have evolved diverse anti-CRISPR (Acr) proteins that subvert these immune systems. The adaptive immune system in Pseudomonas aeruginosa (type I-F) relies on a 350 kDa CRISPR RNA (crRNA)-guided surveillance complex (Csy complex) to bind foreign DNA and recruit a trans-acting nuclease for target degradation. Here, we report the cryo-electron microscopy (cryo-EM) structure of the Csy complex bound to two different Acr proteins, AcrF1 and AcrF2, at an average resolution of 3.4 Å. The structure explains the molecular mechanism for immune system suppression, and structure-guided mutations show that the Acr proteins bind to residues essential for crRNA-mediated detection of DNA. Collectively, these data provide a snapshot of an ongoing molecular arms race between viral suppressors and the immune system they target.
EMDB-8624, PDB-5uz9: Cryo EM structure of anti-CRISPRs, AcrF1 and AcrF2, bound to type I-F crRNA-guided CRISPR surveillance complex 手法: EM (単粒子) / 解像度: 3.4 Å