[2025] Structural Investigation of the Anti-CRISPR Protein AcrIE7
Journal
Proteins: Structure, Function, and Bioinformatics
Authors
Kang, J.#, Park, C.#, Lee, G.#, Koo, J., Oh, H., Kim, E.-H., Bae, E.* Suh, J.-Y.*
#Denotes Equal Contribution
*Denotes Corresponding Author
Abstract
The CRISPR- Cas system is an adaptive immune system in prokaryotes that provides protection against bacteriophages. As a countermeasure, bacteriophages have evolved various anti- CRISPR proteins that neutralize CRISPR- Cas immunity. Here, we report the structural and functional investigation of AcrIE7, which inhibits the type I-E CRISPR- Cas system in Pseudomonas aeruginosa. We determined both crystal and solution structures of AcrIE7, which revealed a novel helical fold. In binding assays using various biochemical methods, AcrIE7 did not tightly interact with a single Cas component in the type I-E Cascade complex or the CRISPR adaptation machinery. In contrast, AlphaFold modeling with our experimentally determined AcrIE7 structure predicted that AcrIE7 interacts with Cas3 in the type I-E CRISPR- Cas system in P. aeruginosa. Our findings are consistent with a model where AcrIE7 inhibits Cas3 and also highlight the effectiveness and limitations of AlphaFold modeling.
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doi: 10.1002/prot.26832
Journal
Proteins: Structure, Function, and Bioinformatics
Authors
Kang, J.#, Park, C.#, Lee, G.#, Koo, J., Oh, H., Kim, E.-H., Bae, E.* Suh, J.-Y.*
#Denotes Equal Contribution
*Denotes Corresponding Author
Abstract
The CRISPR- Cas system is an adaptive immune system in prokaryotes that provides protection against bacteriophages. As a countermeasure, bacteriophages have evolved various anti- CRISPR proteins that neutralize CRISPR- Cas immunity. Here, we report the structural and functional investigation of AcrIE7, which inhibits the type I-E CRISPR- Cas system in Pseudomonas aeruginosa. We determined both crystal and solution structures of AcrIE7, which revealed a novel helical fold. In binding assays using various biochemical methods, AcrIE7 did not tightly interact with a single Cas component in the type I-E Cascade complex or the CRISPR adaptation machinery. In contrast, AlphaFold modeling with our experimentally determined AcrIE7 structure predicted that AcrIE7 interacts with Cas3 in the type I-E CRISPR- Cas system in P. aeruginosa. Our findings are consistent with a model where AcrIE7 inhibits Cas3 and also highlight the effectiveness and limitations of AlphaFold modeling.
Download link
doi: 10.1002/prot.26832