2I9G

DNA Polymerase Beta with a Benzo[c]phenanthrene diol epoxide adducted guanine base


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of DNA polymerase beta with a benzo[c]phenanthrene diol epoxide-adducted template exhibits mutagenic features.

Batra, V.K.Shock, D.D.Prasad, R.Beard, W.A.Hou, E.W.Pedersen, L.C.Sayer, J.M.Yagi, H.Kumar, S.Jerina, D.M.Wilson, S.H.

(2006) Proc.Natl.Acad.Sci.Usa 103: 17231-17236

  • DOI: 10.1073/pnas.0605069103

  • PubMed Abstract: 
  • We have determined the crystal structure of the human base excision repair enzyme DNA polymerase beta (Pol beta) in complex with a 1-nt gapped DNA substrate containing a template N2-guanine adduct of the tumorigenic (-)-benzo[c]phenanthrene 4R,3S-dio ...

    We have determined the crystal structure of the human base excision repair enzyme DNA polymerase beta (Pol beta) in complex with a 1-nt gapped DNA substrate containing a template N2-guanine adduct of the tumorigenic (-)-benzo[c]phenanthrene 4R,3S-diol 2S,1R-epoxide in the gap. Nucleotide insertion opposite this adduct favors incorrect purine nucleotides over the correct dCMP and hence can be mutagenic. The structure reveals that the phenanthrene ring system is stacked with the base pair immediately 3' to the modified guanine, thereby occluding the normal binding site for the correct incoming nucleoside triphosphate. The modified guanine base is displaced downstream and prevents the polymerase from achieving the catalytically competent closed conformation. The incoming nucleotide binding pocket is distorted, and the adducted deoxyguanosine is in a syn conformation, exposing its Hoogsteen edge, which can hydrogen-bond with dATP or dGTP. In a reconstituted base excision repair system, repair of a deaminated cytosine (i.e., uracil) opposite the adducted guanine was dramatically decreased at the Pol beta insertion step, but not blocked. The efficiency of gap-filling dCMP insertion opposite the adduct was diminished by >6 orders of magnitude compared with an unadducted templating guanine. In contrast, significant misinsertion of purine nucleotides (but not dTMP) opposite the adducted guanine was observed. Pol beta also misinserts a purine nucleotide opposite the adduct with ungapped DNA and exhibits limited bypass DNA synthesis. These results indicate that Pol beta-dependent base excision repair of uracil opposite, or replication through, this bulky DNA adduct can be mutagenic.


    Organizational Affiliation

    Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
DNA polymerase beta
A
335Homo sapiensMutation(s): 0 
Gene Names: POLB
EC: 2.7.7.7, 4.2.99.-
Find proteins for P06746 (Homo sapiens)
Go to Gene View: POLB
Go to UniProtKB:  P06746
Entity ID: 1
MoleculeChainsLengthOrganism
5'-D(P*GP*TP*CP*GP*G)-3'D5N/A
Entity ID: 2
MoleculeChainsLengthOrganism
5'-D(*GP*CP*TP*GP*AP*TP*GP*CP*GP*C)-3'P10N/A
Entity ID: 3
MoleculeChainsLengthOrganism
5'-D(*CP*CP*GP*AP*CP*GP*GP*CP*GP*CP*AP*TP*CP*AP*GP*C)-3'T16N/A
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

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Download CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

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Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
BPI
Query on BPI

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Download CCD File 
T
(1S)-1,2,3,4-TETRAHYDRO-BENZO[C]PHENANTHRENE-2,3,4-TRIOL
1S-TRANS-ANTI-BENZO[C]PHENANTHRENE
C18 H16 O3
WCUHTHVUZQCBTI-KBAYOESNSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
DOC
Query on DOC
P
DNA LINKINGC9 H14 N3 O6 PDC
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.200 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 54.550α = 90.00
b = 78.900β = 105.63
c = 54.950γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
HKL-2000data collection
SCALEPACKdata scaling
CNSphasing
HKL-2000data reduction

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-10-24
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance