1VY8: Crystal Structure Of The E. Coli Crispr Rna-guided Surveillance Complex, Cascade

Clustered regularly interspaced short palindromic repeats (CRISPRs) are essential components of RNA-guided adaptive immune systems that protect bacteria and archaea from viruses and plasmids. In Escherichia coli, short CRISPR-derived RNAs (crRNAs) assemble into a 405 kDa multi-subunit surveillance complex called Cascade (CRISPR-associated complex for antiviral defense). Here, we present the 3.24 A resolution x-ray crystal structure of Cascade. Eleven proteins and a 61-nucleotide crRNA assemble into a sea-horse-shaped architecture that binds double-stranded DNA targets complementary to the crRNA-guide sequence. Conserved sequences on the 3'- and 5'-ends of the crRNA are anchored by proteins at opposite ends of the complex, while the guide sequence is displayed along a helical assembly of six interwoven subunits that present 5-nucleotide segments of the crRNA in pseudo A-form configuration. The structure of Cascade suggests a mechanism for assembly and provides insights into the mechanisms of target recognition.
PDB ID: 1VY8Download
MMDB ID: 122470
PDB Deposition Date: 2014/6/28
Updated in MMDB: 2014/08
Experimental Method:
x-ray diffraction
Resolution: 3.24  Å
Source Organism:
Escherichia coli K-12
Similar Structures:
Biological Unit for 1VY8: dodecameric; determined by author
Molecular Components in 1VY8
Label Count Molecule
Proteins (11 molecules)
Crispr System Cascade Subunit Casb
Molecule annotation
Crispr System Cascade Subunit Casc
Molecule annotation
Crispr System Cascade Subunit Casd
Molecule annotation
Crispr System Cascade Subunit Case
Molecule annotation
Crispr System Cascade Subunit Casa
Molecule annotation
Nucleotide(1 molecule)
Escherichia Coli Strain Ecor44 Cluster 1 Crispr Region
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB