4HNO

High resolution crystal structure of DNA Apurinic/apyrimidinic (AP) endonuclease IV Nfo from Thermatoga maritima


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.92 Å
  • R-Value Free: 0.139 
  • R-Value Work: 0.125 
  • R-Value Observed: 0.126 

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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 stages of base repair ...

    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
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Probable endonuclease 4 A288Thermotoga maritima MSB8Mutation(s): 0 
Gene Names: nfoTM_0362
EC: 3.1.21.2
Find proteins for Q9WYJ7 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099))
Explore Q9WYJ7 
Go to UniProtKB:  Q9WYJ7
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.92 Å
  • R-Value Free: 0.139 
  • R-Value Work: 0.125 
  • R-Value Observed: 0.126 
  • Space Group: P 61
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 123.37α = 90
b = 123.37β = 90
c = 35.395γ = 120
Software Package:
Software NamePurpose
SCALEPACKdata scaling
EPMRphasing
PHENIXrefinement
PDB_EXTRACTdata extraction
DENZOdata reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

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