4QQW

Crystal structure of T. fusca Cas3


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.664 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.173 

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:  

  • 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, ...

    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

    1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA. [2].




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CRISPR-associated helicase, Cas3 family
A, C, E, G
964Thermobifida fusca (strain YX)Mutation(s): 0 
Find proteins for Q47PJ0 (Thermobifida fusca (strain YX))
Go to UniProtKB:  Q47PJ0
Entity ID: 2
MoleculeChainsLengthOrganism
DNA (5'-D(P*AP*AP*AP*AP*AP*AP*AP*AP*AP*AP*AP*A)-3')B,D,F,H12N/A
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FE
Query on FE

Download SDF File 
Download CCD File 
A, C, E, G
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.664 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.173 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 85.789α = 90.00
b = 218.542β = 105.00
c = 123.749γ = 90.00
Software Package:
Software NamePurpose
PHENIXphasing
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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