6EXP

Crystal structure of the SIRV3 AcrID1 (gp02) anti-CRISPR protein

Summary for 6EXP

• Entry DOI: 10.2210/pdb6exp/pdb
• Descriptor: SIRV3 AcrID1 (gp02) anti-CRISPR protein (2 entities in total)
• Functional Keywords: anti-crispr, crispr-cas, sulfolobus islandicus rod shaped virus 2, inhibitor, sirv3, viral protein
• Biological source: Sulfolobus islandicus rudivirus 3
• Total number of polymer chains: 6
• Total formula weight: 78520.16

Authors

He, F.,Bhoobalan-Chitty, Y.,Van, L.B.,Kjeldsen, A.L.,Dedola, M.,Makarova, K.S.,Koonin, E.V.,Brodersen, D.E.,Peng, X. (deposition date: 2017-11-08, release date: 2018-01-31, Last modification date: 2024-05-08)

Primary citation

He, F.,Bhoobalan-Chitty, Y.,Van, L.B.,Kjeldsen, A.L.,Dedola, M.,Makarova, K.S.,Koonin, E.V.,Brodersen, D.E.,Peng, X.
Anti-CRISPR proteins encoded by archaeal lytic viruses inhibit subtype I-D immunity.
Nat Microbiol, 3:461-469, 2018

PubMed Abstract: Viruses employ a range of strategies to counteract the prokaryotic adaptive immune system, clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas), including mutational escape and physical blocking of enzymatic function using anti-CRISPR proteins (Acrs). Acrs have been found in many bacteriophages but so far not in archaeal viruses, despite the near ubiquity of CRISPR-Cas systems in archaea. Here, we report the functional and structural characterization of two archaeal Acrs from the lytic rudiviruses, SIRV2 and SIRV3. We show that a 4 kb deletion in the SIRV2 genome dramatically reduces infectivity in Sulfolobus islandicus LAL14/1 that carries functional CRISPR-Cas subtypes I-A, I-D and III-B. Subsequent insertion of a single gene from SIRV3, gp02 (AcrID1), which is conserved in the deleted fragment, successfully restored infectivity. We demonstrate that AcrID1 protein inhibits the CRISPR-Cas subtype I-D system by interacting directly with Cas10d protein, which is required for the interference stage. Sequence and structural analysis of AcrID1 show that it belongs to a conserved family of compact, dimeric αβ-sandwich proteins characterized by extreme pH and temperature stability and a tendency to form protein fibres. We identify about 50 homologues of AcrID1 in four archaeal viral families demonstrating the broad distribution of this group of anti-CRISPR proteins.

PubMed: 29507349
DOI: 10.1038/s41564-018-0120-z

Experimental method

X-RAY DIFFRACTION (1.93 Å)