4F3E

Crystal Structure of Thermus thermophilus HB8 CasA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.195 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal Structure of the Largest Subunit of a Bacterial RNA-guided Immune Complex and Its Role in DNA Target Binding.

Mulepati, S.Orr, A.Bailey, S.

(2012) J.Biol.Chem. 287: 22445-22449

  • DOI: 10.1074/jbc.C112.379503

  • PubMed Abstract: 
  • Prokaryotes make use of small RNAs encoded by CRISPR (clustered regularly interspaced short palindromic repeat) loci to provide immunity against bacteriophage or plasmid invasion. In Escherichia coli, the CRISPR-associated complex for antiviral defen ...

    Prokaryotes make use of small RNAs encoded by CRISPR (clustered regularly interspaced short palindromic repeat) loci to provide immunity against bacteriophage or plasmid invasion. In Escherichia coli, the CRISPR-associated complex for antiviral defense (Cascade) utilizes these RNAs to target foreign DNA for destruction. CasA, the largest subunit of Cascade, is essential for its function. Here we report the crystal structure of Thermus thermophilus CasA. The structure is composed of two domains that are arranged in a chair-like conformation with a novel fold forming the larger N-terminal domain. Docking of the crystal structure into cryo-electron microscopy maps reveals two loops in CasA that likely have important functions in DNA target binding. Finally, DNA binding experiments show that CasA is essential for binding of Cascade to DNA target.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Johns Hopkins School of Public Health, Baltimore, Maryland 21205, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CasA
A, B
502Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)Mutation(s): 0 
Gene Names: cse1 (casA)
Find proteins for Q53VY1 (Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579))
Go to UniProtKB:  Q53VY1
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.195 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 93.888α = 90.00
b = 47.926β = 97.52
c = 129.168γ = 90.00
Software Package:
Software NamePurpose
SOLVEphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
Blu-Icedata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-05-23
    Type: Initial release
  • Version 1.1: 2012-06-06
    Type: Database references
  • Version 1.2: 2012-07-18
    Type: Database references