2ABK

REFINEMENT OF THE NATIVE STRUCTURE OF ENDONUCLEASE III TO A RESOLUTION OF 1.85 ANGSTROM


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.185 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Novel DNA binding motifs in the DNA repair enzyme endonuclease III crystal structure.

Thayer, M.M.Ahern, H.Xing, D.Cunningham, R.P.Tainer, J.A.

(1995) EMBO J. 14: 4108-4120


  • PubMed Abstract: 
  • The 1.85 A crystal structure of endonuclease III, combined with mutational analysis, suggests the structural basis for the DNA binding and catalytic activity of the enzyme. Helix-hairpin-helix (HhH) and [4Fe-4S] cluster loop (FCL) motifs, which we ha ...

    The 1.85 A crystal structure of endonuclease III, combined with mutational analysis, suggests the structural basis for the DNA binding and catalytic activity of the enzyme. Helix-hairpin-helix (HhH) and [4Fe-4S] cluster loop (FCL) motifs, which we have named for their secondary structure, bracket the cleft separating the two alpha-helical domains of the enzyme. These two novel DNA binding motifs and the solvent-filled pocket in the cleft between them all lie within a positively charged and sequence-conserved surface region. Lys120 and Asp138, both shown by mutagenesis to be catalytically important, lie at the mouth of this pocket, suggesting that this pocket is part of the active site. The positions of the HhH motif and protruding FCL motif, which contains the DNA binding residue Lys191, can accommodate B-form DNA, with a flipped-out base bound within the active site pocket. The identification of HhH and FCL sequence patterns in other DNA binding proteins suggests that these motifs may be a recurrent structural theme for DNA binding proteins.


    Related Citations: 
    • Atomic Structure of the DNA Repair [4Fe-4S] Enzyme Endonuclease III
      Kuo, C.-F.,Mcree, D.E.,Fisher, C.L.,Handley, S.,Cunningham, R.P.,Tainer, J.A.
      (1992) Science 258: 434
    • Crystallization and Crystallographic Characterization of the Iron-Sulfur Containing DNA-Repair Enzyme Endonuclease III from Escherichia Coli Enzyme Endonuclease III
      Kuo, C.-F.,Mcree, D.E.,Cunningham, R.P.,Tainer, J.A.
      (1992) J.Mol.Biol. 227: 347


    Organizational Affiliation

    Scripps Research Institute, Department of Molecular Biology-MB4, La Jolla, CA 92037, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ENDONUCLEASE III
A
211Escherichia coli (strain K12)Gene Names: nth
EC: 4.2.99.18
Find proteins for P0AB83 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AB83
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SF4
Query on SF4

Download SDF File 
Download CCD File 
A
IRON/SULFUR CLUSTER
Fe4 S4
LJBDFODJNLIPKO-VKOJMFJBAC
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.185 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 48.500α = 90.00
b = 65.800β = 90.00
c = 86.800γ = 90.00
Software Package:
Software NamePurpose
XENGENdata reduction
X-PLORrefinement
X-PLORmodel building
X-PLORphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1995-10-15
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-11-29
    Type: Derived calculations, Other