5CFE

Bacillus subtilis AP endonuclease ExoA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.84 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.169 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural comparison of AP endonucleases from the exonuclease III family reveals new amino acid residues in human AP endonuclease 1 that are involved in incision of damaged DNA.

Redrejo-Rodriguez, M.Vigouroux, A.Mursalimov, A.Grin, I.Alili, D.Koshenov, Z.Akishev, Z.Maksimenko, A.Bissenbaev, A.K.Matkarimov, B.T.Saparbaev, M.Ishchenko, A.A.Morera, S.

(2016) Biochimie 128-129: 20-33

  • DOI: 10.1016/j.biochi.2016.06.011
  • Primary Citation of Related Structures:  
    5CFE, 5CFG

  • PubMed Abstract: 
  • Oxidatively damaged DNA bases are substrates for two overlapping repair pathways: DNA glycosylase-initiated base excision repair (BER) and apurinic/apyrimidinic (AP) endonuclease-initiated nucleotide incision repair (NIR). In the BER pathway, an AP endonuclease cleaves DNA at AP sites and 3'-blocking moieties generated by DNA glycosylases, whereas in the NIR pathway, the same AP endonuclease incises DNA 5' to an oxidized base ...

    Oxidatively damaged DNA bases are substrates for two overlapping repair pathways: DNA glycosylase-initiated base excision repair (BER) and apurinic/apyrimidinic (AP) endonuclease-initiated nucleotide incision repair (NIR). In the BER pathway, an AP endonuclease cleaves DNA at AP sites and 3'-blocking moieties generated by DNA glycosylases, whereas in the NIR pathway, the same AP endonuclease incises DNA 5' to an oxidized base. The majority of characterized AP endonucleases possess classic BER activities, and approximately a half of them can also have a NIR activity. At present, the molecular mechanism underlying DNA substrate specificity of AP endonucleases remains unclear mainly due to the absence of a published structure of the enzyme in complex with a damaged base. To identify critical residues involved in the NIR function, we performed biochemical and structural characterization of Bacillus subtilis AP endonuclease ExoA and compared its crystal structure with the structures of other AP endonucleases: Escherichia coli exonuclease III (Xth), human APE1, and archaeal Mth212. We found conserved amino acid residues in the NIR-specific enzymes APE1, Mth212, and ExoA. Four of these positions were studied by means of point mutations in APE1: we applied substitution with the corresponding residue found in NIR-deficient E. coli Xth (Y128H, N174Q, G231S, and T268D). The APE1-T268D mutant showed a drastically decreased NIR activity and an inverted Mg(2+) dependence of the AP site cleavage activity, which is in line with the presence of an aspartic residue at the equivalent position among other known NIR-deficient AP endonucleases. Taken together, these data show that NIR is an evolutionarily conserved function in the Xth family of AP endonucleases.


    Organizational Affiliation

    Institute for Integrative Biology of the Cell (I2BC), CNRS CEA Univ Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette 91198, France. Electronic address: solange.morera@i2bc.paris-saclay.fr.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ExodeoxyribonucleaseA252Bacillus subtilis subsp. subtilis str. 168Mutation(s): 0 
Gene Names: exoABSU40880
EC: 3.1.11.2
UniProt
Find proteins for P37454 (Bacillus subtilis (strain 168))
Explore P37454 
Go to UniProtKB:  P37454
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP37454
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.84 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.169 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.28α = 90
b = 61.92β = 90
c = 73.36γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-07-06
    Type: Initial release
  • Version 1.1: 2016-10-05
    Changes: Database references