7BB5

Crystal structure of anti-CRISPR protein AcrIF9

Summary for 7BB5

• Entry DOI: 10.2210/pdb7bb5/pdb
• Descriptor: AcrIF9 (2 entities in total)
• Functional Keywords: anti-crispr, acrif9, crispr-cas, type if, viral protein
• Biological source: Aggregatibacter actinomycetemcomitans serotype e str. SC1083
• Total number of polymer chains: 1
• Total formula weight: 10330.41

Authors

Tamulaitiene, G.,Sinkunas, T.,Kupcinskaite, E. (deposition date: 2020-12-17, release date: 2021-11-24, Last modification date: 2024-05-01)

Primary citation

Kupcinskaite, E.,Tutkus, M.,Kopustas, A.,Asmontas, S.,Jankunec, M.,Zaremba, M.,Tamulaitiene, G.,Sinkunas, T.
Disarming of type I-F CRISPR-Cas surveillance complex by anti-CRISPR proteins AcrIF6 and AcrIF9.
Sci Rep, 12:15548-15548, 2022

PubMed Abstract: CRISPR-Cas systems are prokaryotic adaptive immune systems that protect against phages and other invading nucleic acids. The evolutionary arms race between prokaryotes and phages gave rise to phage anti-CRISPR (Acr) proteins that act as a counter defence against CRISPR-Cas systems by inhibiting the effector complex. Here, we used a combination of bulk biochemical experiments, X-ray crystallography and single-molecule techniques to explore the inhibitory activity of AcrIF6 and AcrIF9 proteins against the type I-F CRISPR-Cas system from Aggregatibacter actinomycetemcomitans (Aa). We showed that AcrIF6 and AcrIF9 proteins hinder Aa-Cascade complex binding to target DNA. We solved a crystal structure of Aa1-AcrIF9 protein, which differ from other known AcrIF9 proteins by an additional structurally important loop presumably involved in the interaction with Cascade. We revealed that AcrIF9 association with Aa-Cascade promotes its binding to off-target DNA sites, which facilitates inhibition of CRISPR-Cas protection.

PubMed: 36109551
DOI: 10.1038/s41598-022-19797-y

Experimental method

X-RAY DIFFRACTION (2.3 Å)