6BOU

Human APE1 substrate complex with an T/C mismatch adjacent the THF


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.538 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.208 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Apurinic/apyrimidinic (AP) endonuclease 1 processing of AP sites with 5' mismatches.

Fairlamb, M.S.Whitaker, A.M.Freudenthal, B.D.

(2018) Acta Crystallogr D Struct Biol 74: 760-768

  • DOI: 10.1107/S2059798318003340
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Despite the DNA duplex being central to biological functions, many intricacies of this molecule, including the dynamic nature of mismatched base pairing, are still unknown. The unique conformations adopted by DNA mismatches can provide insight into t ...

    Despite the DNA duplex being central to biological functions, many intricacies of this molecule, including the dynamic nature of mismatched base pairing, are still unknown. The unique conformations adopted by DNA mismatches can provide insight into the forces at play between nucleotides. Moreover, DNA-binding proteins apply their own individualized steric and electrochemical influences on the nucleotides that they interact with, further altering base-pairing conformations. Here, seven X-ray crystallographic structures of the human nuclease apurinic/apyrimidinic (AP) endonuclease 1 (APE1) in complex with its substrate target flanked by a 5' mismatch are reported. The structures reveal how APE1 influences the conformations of a variety of different mismatched base pairs. Purine-purine mismatches containing a guanine are stabilized by a rotation of the guanine residue about the N-glycosidic bond to utilize the Hoogsteen edge for hydrogen bonding. Interestingly, no rotation of adenine, the other purine, is observed. Mismatches involving both purine and pyrimidine bases adopt wobble conformations to accommodate the mismatch. Pyrimidine-pyrimidine mismatches also wobble; however, the smaller profile of a pyrimidine base results in a gap between the Watson-Crick faces that is reduced by a C1'-C1' compression. These results advance our understanding of mismatched base pairing and the influence of a bound protein.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66016, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DNA-(apurinic or apyrimidinic site) lyase
A, B
318Homo sapiensMutation(s): 1 
Gene Names: APEX1 (APE, APE1, APEX, APX, HAP1, REF1)
EC: 3.1.-.-, 4.2.99.18
Find proteins for P27695 (Homo sapiens)
Go to Gene View: APEX1
Go to UniProtKB:  P27695
Entity ID: 2
MoleculeChainsLengthOrganism
21-mer DNAP21synthetic construct
Entity ID: 3
MoleculeChainsLengthOrganism
21-mer DNAV21synthetic construct
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
DV3
Query on DV3
P
NON-POLYMERC5 H11 O5 P S

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.538 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.208 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 44.303α = 83.35
b = 60.909β = 78.50
c = 73.314γ = 87.34
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
HKL-2000data scaling
PHENIXrefinement
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
NIHUnited StatesES024431

Revision History 

  • Version 1.0: 2018-08-15
    Type: Initial release