Recognition and Cleavage of a non-structured CRISPR RNA by its Processing Endoribonuclease Cas6

Experimental Data Snapshot

  • Resolution: 2.48 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.207 

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Recognition and cleavage of a nonstructured CRISPR RNA by its processing endoribonuclease Cas6.

Shao, Y.Li, H.

(2013) Structure 21: 385-393

  • DOI: https://doi.org/10.1016/j.str.2013.01.010
  • Primary Citation of Related Structures:  
    4ILL, 4ILM, 4ILR

  • PubMed Abstract: 

    Clustered regularly interspaced short palindromic repeats (CRISPRs) confer adaptive immunity to prokaryotes through a small RNA-mediated mechanism. Specific endoribonucleases are required by all CRISPR-bearing organisms to process CRISPR RNAs into small RNA that serve as guides for defensive effector complexes. The molecular mechanism of how the endoribonucleases process the class of CRISPR RNA containing no predicted secondary structural features remains largely elusive. Here, we report cocrystal structures of a processing endoribonuclease bound with a noncleavable RNA substrate and its product-like fragment derived from a nonpalindramic repeat. The enzyme stabilizes a short RNA stem-loop structure near the cleavage site and cleaves the phosphodiester bond using an active site comprised of arginine and lysine residues. The distinct RNA binding and cleavage mechanisms underline the diversity in CRISPR RNA processing.

  • Organizational Affiliation

    Institute of Molecular Biophysics, Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA


Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CRISPR-associated endoribonuclease Cas6 2A,
C [auth B]
289Saccharolobus solfataricus P2Mutation(s): 0 
Gene Names: cas6bSSO2004
EC: 3.1
Find proteins for Q97WV8 (Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2))
Explore Q97WV8 
Go to UniProtKB:  Q97WV8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ97WV8
Sequence Annotations
  • Reference Sequence

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Entity ID: 2
MoleculeChains LengthOrganismImage
D [auth C]
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.48 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.207 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 159.735α = 90
b = 68.542β = 119.12
c = 79.831γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-03-20
    Type: Initial release
  • Version 1.1: 2013-05-01
    Changes: Database references
  • Version 1.2: 2024-02-28
    Changes: Data collection, Database references, Derived calculations