4IEM

Human apurinic/apyrimidinic endonuclease (APE1) with product DNA and Mg2+

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.39 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.210 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history. 


Literature

Conserved Structural Chemistry for Incision Activity in Structurally Non-homologous Apurinic/Apyrimidinic Endonuclease APE1 and Endonuclease IV DNA Repair Enzymes.

Tsutakawa, S.E., Shin, D.S., Mol, C.D., Izumi, T., Arvai, A.S., Mantha, A.K., Szczesny, B., Ivanov, I.N., Hosfield, D.J., Maiti, B., Pique, M.E., Frankel, K.A., Hitomi, K., Cunningham, R.P., Mitra, S., Tainer, J.A.

(2013) J Biol Chem 288: 8445-8455

  • DOI: 10.1074/jbc.M112.422774
  • Primary Citation of Related Structures:  
    4HNO, 4IEM

  • PubMed Abstract: 

    • Non-coding apurinic/apyrimidinic (AP) sites in DNA form spontaneously and as DNA base excision repair intermediates are the most common toxic and mutagenic in vivo DNA lesion. For repair, AP sites must be processed by 5' AP endonucleases in initial stage ...

    Non-coding apurinic/apyrimidinic (AP) sites in DNA form spontaneously and as DNA base excision repair intermediates are the most common toxic and mutagenic in vivo DNA lesion. For repair, AP sites must be processed by 5' AP endonucleases in initial stages of base repair. Human APE1 and bacterial Nfo represent the two conserved 5' AP endonuclease families in the biosphere; they both recognize AP sites and incise the phosphodiester backbone 5' to the lesion, yet they lack similar structures and metal ion requirements. Here, we determined and analyzed crystal structures of a 2.4 Å resolution APE1-DNA product complex with Mg(2+) and a 0.92 Å Nfo with three metal ions. Structural and biochemical comparisons of these two evolutionarily distinct enzymes characterize key APE1 catalytic residues that are potentially functionally similar to Nfo active site components, as further tested and supported by computational analyses. We observe a magnesium-water cluster in the APE1 active site, with only Glu-96 forming the direct protein coordination to the Mg(2+). Despite differences in structure and metal requirements of APE1 and Nfo, comparison of their active site structures surprisingly reveals strong geometric conservation of the catalytic reaction, with APE1 catalytic side chains positioned analogously to Nfo metal positions, suggesting surprising functional equivalence between Nfo metal ions and APE1 residues. The finding that APE1 residues are positioned to substitute for Nfo metal ions is supported by the impact of mutations on activity. Collectively, the results illuminate the activities of residues, metal ions, and active site features for abasic site endonucleases.

    Organizational Affiliation: 

    Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.



Macromolecules

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(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
DNA-(apurinic or apyrimidinic site) lyase A, B, C, D317Homo sapiensMutation(s): 0 
Gene Names: APE, APE1, APEX, APEX1, APX, HAP1, REF1
EC: 3.1 (PDB Primary Data), 4.2.99.18 (PDB Primary Data)
Find proteins for P27695 (Homo sapiens)
Explore P27695 
Go to UniProtKB:  P27695
NIH Common Fund Data Resources
PHAROS:  P27695
GTEx:  ENSG00000100823
Protein Feature View
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  • Reference Sequence
  • Find similar nucleic acids by:  Sequence   |   Structure
    • Entity ID: 2
    MoleculeChainsLengthOrganismImage
    DNA (5'-D(*GP*CP*TP*AP*C)-3')E, H, K, N5synthetic construct
    • Find similar nucleic acids by:  Sequence   |   Structure
      • Entity ID: 3
      MoleculeChainsLengthOrganismImage
      DNA (5'-D(P*(3DR)P*GP*AP*TP*CP*G)-3')F, I, L, O6synthetic construct
      • Find similar nucleic acids by:  Sequence   |   Structure
        • Entity ID: 4
        MoleculeChainsLengthOrganismImage
        DNA (5'-D(*CP*GP*AP*TP*CP*GP*GP*TP*AP*GP*C)-3')G, J, M, P11synthetic construct
        Experimental Data & Validation

        Experimental Data

        • Method: X-RAY DIFFRACTION
        • Resolution: 2.39 Å
        • R-Value Free: 0.246 
        • R-Value Work: 0.208 
        • R-Value Observed: 0.210 
        • Space Group: P 1 21 1
        Unit Cell:
        Length ( Å )Angle ( ˚ )
        a = 104.639α = 90
        b = 74.09β = 111.98
        c = 112.138γ = 90
        Software Package:
        Software NamePurpose
        SCALEPACKdata scaling
        AMoREphasing
        PHENIXrefinement
        PDB_EXTRACTdata extraction
        DENZOdata reduction

        Structure Validation

        View Full Validation Report


        View more in-depth experimental data

        Entry History 

        Deposition Data

        Revision History 

        • Version 1.0: 2013-01-23
          Type: Initial release
        • Version 1.1: 2013-02-13
          Changes: Database references, Derived calculations, Other
        • Version 1.2: 2013-04-10
          Changes: Database references
        • Version 1.3: 2017-11-15
          Changes: Refinement description