4QQW

Crystal structure of T. fusca Cas3


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.66 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.174 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structures of CRISPR Cas3 offer mechanistic insights into Cascade-activated DNA unwinding and degradation.

Huo, Y.Nam, K.H.Ding, F.Lee, H.Wu, L.Xiao, Y.Farchione, M.D.Zhou, S.Rajashankar, K.Kurinov, I.Zhang, R.Ke, A.

(2014) Nat Struct Mol Biol 21: 771-777

  • DOI: 10.1038/nsmb.2875
  • Primary Citation of Related Structures:  
    4QQW, 4QQX, 4QQY, 4QQZ

  • PubMed Abstract: 
  • CRISPR drives prokaryotic adaptation to invasive nucleic acids such as phages and plasmids, using an RNA-mediated interference mechanism. Interference in type I CRISPR-Cas systems requires a targeting Cascade complex and a degradation machine, Cas3, which contains both nuclease and helicase activities ...

    CRISPR drives prokaryotic adaptation to invasive nucleic acids such as phages and plasmids, using an RNA-mediated interference mechanism. Interference in type I CRISPR-Cas systems requires a targeting Cascade complex and a degradation machine, Cas3, which contains both nuclease and helicase activities. Here we report the crystal structures of Thermobifida fusca Cas3 bound to single-stranded (ss) DNA substrate and show that it is an obligate 3'-to-5' ssDNase that preferentially accepts substrate directly from the helicase moiety. Conserved residues in the HD-type nuclease coordinate two irons for ssDNA cleavage. We demonstrate ATP coordination and conformational flexibility of the SF2-type helicase domain. Cas3 is specifically guided toward Cascade-bound target DNA by a PAM sequence, through physical interactions with both the nontarget substrate strand and the CasA protein. The sequence of recognition events ensures well-controlled DNA targeting and degradation of foreign DNA by Cascade and Cas3.


    Organizational Affiliation

    Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA.



Macromolecules

Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CRISPR-associated helicase, Cas3 family ACEG964Thermobifida fusca YXMutation(s): 0 
Gene Names: Tfu_1593
Find proteins for Q47PJ0 (Thermobifida fusca (strain YX))
Explore Q47PJ0 
Go to UniProtKB:  Q47PJ0
Protein Feature View
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  • Reference Sequence
  • Find similar nucleic acids by:  Sequence   |   Structure
  • Entity ID: 2
    MoleculeChainsLengthOrganismImage
    DNA (5'-D(P*AP*AP*AP*AP*AP*AP*AP*AP*AP*AP*AP*A)-3')B, D, F, H12N/A
    Experimental Data & Validation

    Experimental Data

    • Method: X-RAY DIFFRACTION
    • Resolution: 2.66 Å
    • R-Value Free: 0.226 
    • R-Value Work: 0.173 
    • R-Value Observed: 0.174 
    • Space Group: P 1 21 1
    Unit Cell:
    Length ( Å )Angle ( ˚ )
    a = 85.789α = 90
    b = 218.542β = 105
    c = 123.749γ = 90
    Software Package:
    Software NamePurpose
    PHENIXrefinement
    PDB_EXTRACTdata extraction
    HKL-2000data collection
    HKL-2000data reduction
    HKL-2000data scaling
    PHENIXphasing

    Structure Validation

    View Full Validation Report



    Entry History 

    Deposition Data

    Revision History  (Full details and data files)

    • Version 1.0: 2014-08-27
      Type: Initial release
    • Version 1.1: 2014-09-24
      Changes: Database references