6B44

Cryo-EM structure of Type I-F CRISPR crRNA-guided Csy surveillance complex with bound target dsDNA

Summary for 6B44

• Entry DOI: 10.2210/pdb6b44/pdb
• Related: 6B45 6B46 6B47 6B48
• EMDB information: 7048 7049 7050 7051 7052
• Descriptor: CRISPR-associated protein Csy1, CRISPR-associated protein Csy2, CRISPR-associated protein Csy3, ... (7 entities in total)
• Functional Keywords: crispr-cas, immune system-rna-dna complex, immune system/rna/dna
• Biological source: Pseudomonas aeruginosa (strain UCBPP-PA14); More
• Total number of polymer chains: 12
• Total formula weight: 376777.18

Authors

Guo, T.W.,Bartesaghi, A.,Yang, H.,Falconieri, V.,Rao, P.,Merk, A.,Fox, T.,Earl, L.,Patel, D.J.,Subramaniam, S. (deposition date: 2017-09-25, release date: 2017-10-18, Last modification date: 2025-05-28)

Primary citation

Guo, T.W.,Bartesaghi, A.,Yang, H.,Falconieri, V.,Rao, P.,Merk, A.,Eng, E.T.,Raczkowski, A.M.,Fox, T.,Earl, L.A.,Patel, D.J.,Subramaniam, S.
Cryo-EM Structures Reveal Mechanism and Inhibition of DNA Targeting by a CRISPR-Cas Surveillance Complex.
Cell, 171:414-426.e12, 2017

PubMed Abstract: Prokaryotic cells possess CRISPR-mediated adaptive immune systems that protect them from foreign genetic elements, such as invading viruses. A central element of this immune system is an RNA-guided surveillance complex capable of targeting non-self DNA or RNA for degradation in a sequence- and site-specific manner analogous to RNA interference. Although the complexes display considerable diversity in their composition and architecture, many basic mechanisms underlying target recognition and cleavage are highly conserved. Using cryoelectron microscopy (cryo-EM), we show that the binding of target double-stranded DNA (dsDNA) to a type I-F CRISPR system yersinia (Csy) surveillance complex leads to large quaternary and tertiary structural changes in the complex that are likely necessary in the pathway leading to target dsDNA degradation by a trans-acting helicase-nuclease. Comparison of the structure of the surveillance complex before and after dsDNA binding, or in complex with three virally encoded anti-CRISPR suppressors that inhibit dsDNA binding, reveals mechanistic details underlying target recognition and inhibition.

PubMed: 28985564
DOI: 10.1016/j.cell.2017.09.006

Experimental method

ELECTRON MICROSCOPY (2.9 Å)