EMD-32387
Csy1 region of the Csy-AcrIF24-dsDNA(non-sequence-specific) complex
EMD-32387
Single-particle3.2 Å
Deposition: 14/12/2021Map released: 20/04/2022
Last modified: 15/06/2022
Sample Organism:
Pseudomonas aeruginosa
Sample: Csy-AcrIF24-dsDNA
Deposition Authors: Zhang L
,
Feng Y
Sample: Csy-AcrIF24-dsDNA
Deposition Authors: Zhang L
,
Feng Y
Insights into the inhibition of type I-F CRISPR-Cas system by a multifunctional anti-CRISPR protein AcrIF24.
Yang L ,
Zhang L ,
Yin P,
Ding H,
Xiao Y ,
Zeng J ,
Wang W,
Zhou H,
Wang Q,
Zhang Y ,
Chen Z ,
Yang M,
Feng Y
(2022) Nat Commun , 13 , 1931 - 1931
,
Zhang L ,
Yin P,
Ding H,
Xiao Y ,
Zeng J ,
Wang W,
Zhou H,
Wang Q,
Zhang Y ,
Chen Z ,
Yang M,
Feng Y
(2022) Nat Commun , 13 , 1931 - 1931
Abstract:
CRISPR-Cas systems are prokaryotic adaptive immune systems and phages use anti-CRISPR proteins (Acrs) to counteract these systems. Here, we report the structures of AcrIF24 and its complex with the crRNA-guided surveillance (Csy) complex. The HTH motif of AcrIF24 can bind the Acr promoter region and repress its transcription, suggesting its role as an Aca gene in self-regulation. AcrIF24 forms a homodimer and further induces dimerization of the Csy complex. Apart from blocking the hybridization of target DNA to the crRNA, AcrIF24 also induces the binding of non-sequence-specific dsDNA to the Csy complex, similar to AcrIF9, although this binding seems to play a minor role in AcrIF24 inhibitory capacity. Further structural and biochemical studies of the Csy-AcrIF24-dsDNA complexes and of AcrIF24 mutants reveal that the HTH motif of AcrIF24 and the PAM recognition loop of the Csy complex are structural elements essential for this non-specific dsDNA binding. Moreover, AcrIF24 and AcrIF9 display distinct characteristics in inducing non-specific DNA binding. Together, our findings highlight a multifunctional Acr and suggest potential wide distribution of Acr-induced non-specific DNA binding.
CRISPR-Cas systems are prokaryotic adaptive immune systems and phages use anti-CRISPR proteins (Acrs) to counteract these systems. Here, we report the structures of AcrIF24 and its complex with the crRNA-guided surveillance (Csy) complex. The HTH motif of AcrIF24 can bind the Acr promoter region and repress its transcription, suggesting its role as an Aca gene in self-regulation. AcrIF24 forms a homodimer and further induces dimerization of the Csy complex. Apart from blocking the hybridization of target DNA to the crRNA, AcrIF24 also induces the binding of non-sequence-specific dsDNA to the Csy complex, similar to AcrIF9, although this binding seems to play a minor role in AcrIF24 inhibitory capacity. Further structural and biochemical studies of the Csy-AcrIF24-dsDNA complexes and of AcrIF24 mutants reveal that the HTH motif of AcrIF24 and the PAM recognition loop of the Csy complex are structural elements essential for this non-specific dsDNA binding. Moreover, AcrIF24 and AcrIF9 display distinct characteristics in inducing non-specific DNA binding. Together, our findings highlight a multifunctional Acr and suggest potential wide distribution of Acr-induced non-specific DNA binding.