3PS0

The structure of the CRISPR-associated protein, csa2, from Sulfolobus solfataricus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.185 

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This is version 1.3 of the entry. See complete history


Literature

Structural and functional characterization of an archaeal clustered regularly interspaced short palindromic repeat (CRISPR)-associated complex for antiviral defense (CASCADE).

Lintner, N.G.Kerou, M.Brumfield, S.K.Graham, S.Liu, H.Naismith, J.H.Sdano, M.Peng, N.She, Q.Copie, V.Young, M.J.White, M.F.Lawrence, C.M.

(2011) J Biol Chem 286: 21643-21656

  • DOI: 10.1074/jbc.M111.238485
  • Primary Citation of Related Structures:  
    3PS0

  • PubMed Abstract: 
  • In response to viral infection, many prokaryotes incorporate fragments of virus-derived DNA into loci called clustered regularly interspaced short palindromic repeats (CRISPRs). The loci are then transcribed, and the processed CRISPR transcripts are used to target invading viral DNA and RNA ...

    In response to viral infection, many prokaryotes incorporate fragments of virus-derived DNA into loci called clustered regularly interspaced short palindromic repeats (CRISPRs). The loci are then transcribed, and the processed CRISPR transcripts are used to target invading viral DNA and RNA. The Escherichia coli "CRISPR-associated complex for antiviral defense" (CASCADE) is central in targeting invading DNA. Here we report the structural and functional characterization of an archaeal CASCADE (aCASCADE) from Sulfolobus solfataricus. Tagged Csa2 (Cas7) expressed in S. solfataricus co-purifies with Cas5a-, Cas6-, Csa5-, and Cas6-processed CRISPR-RNA (crRNA). Csa2, the dominant protein in aCASCADE, forms a stable complex with Cas5a. Transmission electron microscopy reveals a helical complex of variable length, perhaps due to substoichiometric amounts of other CASCADE components. A recombinant Csa2-Cas5a complex is sufficient to bind crRNA and complementary ssDNA. The structure of Csa2 reveals a crescent-shaped structure unexpectedly composed of a modified RNA-recognition motif and two additional domains present as insertions in the RNA-recognition motif. Conserved residues indicate potential crRNA- and target DNA-binding sites, and the H160A variant shows significantly reduced affinity for crRNA. We propose a general subunit architecture for CASCADE in other bacteria and Archaea.


    Organizational Affiliation

    Thermal Biology Institute, Montana State University, Bozeman, Montana 59717, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CRISPR-Associated protein, CSA2 ABCD328Saccharolobus solfataricus P2Mutation(s): 0 
Gene Names: SSO1442csa2bcas7b
Find proteins for Q97Y91 (Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2))
Explore Q97Y91 
Go to UniProtKB:  Q97Y91
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.185 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 74.642α = 90
b = 120.876β = 90
c = 158.056γ = 90
Software Package:
Software NamePurpose
SOLVEphasing
REFMACrefinement
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: 2011-04-20
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2011-09-14
    Changes: Database references
  • Version 1.3: 2017-10-25
    Changes: Author supporting evidence