3NKD

Structure of CRISP-associated protein Cas1 from Escherichia coli str. K-12


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.217 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

A dual function of the CRISPR-Cas system in bacterial antivirus immunity and DNA repair.

Babu, M.Beloglazova, N.Flick, R.Graham, C.Skarina, T.Nocek, B.Gagarinova, A.Pogoutse, O.Brown, G.Binkowski, A.Phanse, S.Joachimiak, A.Koonin, E.V.Savchenko, A.Emili, A.Greenblatt, J.Edwards, A.M.Yakunin, A.F.

(2011) Mol.Microbiol. 79: 484-502

  • DOI: 10.1111/j.1365-2958.2010.07465.x
  • Primary Citation of Related Structures:  3NKE

  • PubMed Abstract: 
  • Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) and the associated proteins (Cas) comprise a system of adaptive immunity against viruses and plasmids in prokaryotes. Cas1 is a CRISPR-associated protein that is common to all CRISPR ...

    Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) and the associated proteins (Cas) comprise a system of adaptive immunity against viruses and plasmids in prokaryotes. Cas1 is a CRISPR-associated protein that is common to all CRISPR-containing prokaryotes but its function remains obscure. Here we show that the purified Cas1 protein of Escherichia coli (YgbT) exhibits nuclease activity against single-stranded and branched DNAs including Holliday junctions, replication forks and 5'-flaps. The crystal structure of YgbT and site-directed mutagenesis have revealed the potential active site. Genome-wide screens show that YgbT physically and genetically interacts with key components of DNA repair systems, including recB, recC and ruvB. Consistent with these findings, the ygbT deletion strain showed increased sensitivity to DNA damage and impaired chromosomal segregation. Similar phenotypes were observed in strains with deletion of CRISPR clusters, suggesting that the function of YgbT in repair involves interaction with the CRISPRs. These results show that YgbT belongs to a novel, structurally distinct family of nucleases acting on branched DNAs and suggest that, in addition to antiviral immunity, at least some components of the CRISPR-Cas system have a function in DNA repair.


    Organizational Affiliation

    Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario, M5G 1L6, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CRISPR-associated protein Cas1
A, B
305Escherichia coli (strain K12)Gene Names: ygbT (cas1)
EC: 3.1.-.-
Find proteins for Q46896 (Escherichia coli (strain K12))
Go to UniProtKB:  Q46896
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.217 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 78.674α = 90.00
b = 79.300β = 90.00
c = 101.562γ = 90.00
Software Package:
Software NamePurpose
HKL-3000data scaling
HKL-3000data reduction
PHASERphasing
REFMACrefinement
SBC-Collectdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-08-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance