Cas9 Allosteric Inhibition by the Anti-CRISPR Protein AcrIIA6.
Allosteric Regulation
Bacteriophages
/ genetics
Binding Sites
CRISPR-Associated Protein 9
/ genetics
CRISPR-Cas Systems
Clustered Regularly Interspaced Short Palindromic Repeats
DNA
/ genetics
Escherichia coli
/ enzymology
Humans
K562 Cells
Kinetics
Mutation
Protein Binding
Protein Conformation
Streptococcus thermophilus
/ enzymology
Structure-Activity Relationship
Viral Proteins
/ genetics
CRISPR-Cas9
St1Cas9
Streptococcus thermophilus Cas9
anti-CRISPR protein
bacteriophages
cryo-electron microscopy
Journal
Molecular cell
ISSN: 1097-4164
Titre abrégé: Mol Cell
Pays: United States
ID NLM: 9802571
Informations de publication
Date de publication:
19 12 2019
19 12 2019
Historique:
received:
28
05
2019
revised:
02
08
2019
accepted:
06
09
2019
pubmed:
13
10
2019
medline:
20
2
2020
entrez:
13
10
2019
Statut:
ppublish
Résumé
In the arms race against bacteria, bacteriophages have evolved diverse anti-CRISPR proteins (Acrs) that block CRISPR-Cas immunity. Acrs play key roles in the molecular coevolution of bacteria with their predators, use a variety of mechanisms of action, and provide tools to regulate Cas-based genome manipulation. Here, we present structural and functional analyses of AcrIIA6, an Acr from virulent phages, exploring its unique anti-CRISPR action. Our cryo-EM structures and functional data of AcrIIA6 binding to Streptococcus thermophilus Cas9 (St1Cas9) show that AcrIIA6 acts as an allosteric inhibitor and induces St1Cas9 dimerization. AcrIIA6 reduces St1Cas9 binding affinity for DNA and prevents DNA binding within cells. The PAM and AcrIIA6 recognition sites are structurally close and allosterically linked. Mechanistically, AcrIIA6 affects the St1Cas9 conformational dynamics associated with PAM binding. Finally, we identify a natural St1Cas9 variant resistant to AcrIIA6 illustrating Acr-driven mutational escape and molecular diversification of Cas9 proteins.
Identifiants
pubmed: 31604602
pii: S1097-2765(19)30697-5
doi: 10.1016/j.molcel.2019.09.012
pii:
doi:
Substances chimiques
Viral Proteins
0
DNA
9007-49-2
CRISPR-Associated Protein 9
EC 3.1.-
Types de publication
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
922-937.e7Informations de copyright
Copyright © 2019 Elsevier Inc. All rights reserved.