9WA8

Crystal structure of AcrIIA19 from Staphylococcus pseudintermedius

Summary for 9WA8

• Entry DOI: 10.2210/pdb9wa8/pdb
• Descriptor: Anti-CRISPR protein (2 entities in total)
• Functional Keywords: crispr-cas system, anti-crispr protein, acriia19, immune system
• Biological source: Staphylococcus pseudintermedius
• Total number of polymer chains: 4
• Total formula weight: 58181.40

Authors

Kim, G.E.,Kang, Y.J.,Park, H.H. (deposition date: 2025-08-11, release date: 2026-07-08)

Primary citation

Kim, G.E.,Lee, S.Y.,Kang, Y.J.,Bin Jin, H.,Park, H.H.
AcrIIA19 binds to the WED domain and inhibits various Cas9 orthologs at multiple stages.
Commun Biol, 9:136-136, 2025

PubMed Abstract: Anti-CRISPR (Acr) proteins are natural inhibitors of clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein (Cas) systems, providing valuable tools for regulating genome editing. Here, we present the crystal structure of AcrIIA19, a plasmid-encoded Type II-A CRISPR-Cas system inhibitor that targets Cas9. AcrIIA19 adopts a previously uncharacterized fold and forms a stable homodimer. Biochemical assays revealed that AcrIIA19 binds selectively to the wedge (WED) domain of Cas9, a conserved structural interface critical for single guide RNA-DNA duplex stabilization and catalysis. This interaction disrupts Cas9 activity at multiple stages, independent of the order of complex assembly. Notably, AcrIIA19 exhibits broad-spectrum inhibition across divergent Cas9 orthologs, including Streptococcus pyogenes and Staphylococcus aureus Cas9, by exploiting a conserved WED domain vulnerability. Our findings establish AcrIIA19 as a versatile Cas9 inhibitor and highlight the WED domain as a strategic target for developing species-agnostic CRISPR regulatory tools in biotechnology and therapeutic applications.

PubMed: 41430372
DOI: 10.1038/s42003-025-09417-6

Experimental method

X-RAY DIFFRACTION (1.98 Å)