5Y6A

Crystal structure of the anti-CRISPR protein, AcrIIA1

Summary for 5Y6A

• Entry DOI: 10.2210/pdb5y6a/pdb
• Related: 5Y69
• Descriptor: chain A and B (2 entities in total)
• Functional Keywords: unknown function, viral protein
• Biological source: Listeria monocytogenes J0161
• Total number of polymer chains: 2
• Total formula weight: 34936.12

Authors

Ka, D.,An, S.Y.,Suh, J.Y.,Bae, E. (deposition date: 2017-08-11, release date: 2017-11-29, Last modification date: 2023-11-22)

Primary citation

Ka, D.,An, S.Y.,Suh, J.Y.,Bae, E.
Crystal structure of an anti-CRISPR protein, AcrIIA1
Nucleic Acids Res., 46:485-492, 2018

PubMed Abstract: Clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins provide bacteria with RNA-based adaptive immunity against phage infection. To counteract this defense mechanism, phages evolved anti-CRISPR (Acr) proteins that inactivate the CRISPR-Cas systems. AcrIIA1, encoded by Listeria monocytogenes prophages, is the most prevalent among the Acr proteins targeting type II-A CRISPR-Cas systems and has been used as a marker to identify other Acr proteins. Here, we report the crystal structure of AcrIIA1 and its RNA-binding affinity. AcrIIA1 forms a dimer with a novel two helical-domain architecture. The N-terminal domain of AcrIIA1 exhibits a helix-turn-helix motif similar to transcriptional factors. When overexpressed in Escherichia coli, AcrIIA1 associates with RNAs, suggesting that AcrIIA1 functions via nucleic acid recognition. Taken together, the unique structural and functional features of AcrIIA1 suggest its distinct mode of Acr activity, expanding the diversity of the inhibitory mechanisms employed by Acr proteins.

PubMed: 29182776
DOI: 10.1093/nar/gkx1181

Experimental method

X-RAY DIFFRACTION (2 Å)