1X9W

T7 DNA polymerase in complex with a primer/template DNA containing a disordered N-2 aminofluorene on the template, crystallized with dideoxy-ATP as the incoming nucleotide.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.230 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structures of 2-acetylaminofluorene and 2-aminofluorene in complex with T7 DNA polymerase reveal mechanisms of mutagenesis.

Dutta, S.Li, Y.Johnson, D.Dzantiev, L.Richardson, C.C.Romano, L.J.Ellenberger, T.

(2004) Proc.Natl.Acad.Sci.Usa 101: 16186-16191

  • DOI: 10.1073/pnas.0406516101
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The carcinogen 2-acetylaminofluorene forms two major DNA adducts: N-(2'-deoxyguanosin-8-yl)-2-acetylaminofluorene (dG-AAF) and its deacetylated derivative, N-(2'-deoxyguanosin-8-yl)-2-aminofluorene (dG-AF). Although the dG-AAF and dG-AF adducts are d ...

    The carcinogen 2-acetylaminofluorene forms two major DNA adducts: N-(2'-deoxyguanosin-8-yl)-2-acetylaminofluorene (dG-AAF) and its deacetylated derivative, N-(2'-deoxyguanosin-8-yl)-2-aminofluorene (dG-AF). Although the dG-AAF and dG-AF adducts are distinguished only by the presence or absence of an acetyl group, they have profoundly different effects on DNA replication. dG-AAF poses a strong block to DNA synthesis and primarily induces frameshift mutations in bacteria, resulting in the loss of one or two nucleotides during replication past the lesion. dG-AF is less toxic and more easily bypassed by DNA polymerases, albeit with an increased frequency of misincorporation opposite the lesion, primarily resulting in G --> T transversions. We present three crystal structures of bacteriophage T7 DNA polymerase replication complexes, one with dG-AAF in the templating position and two others with dG-AF in the templating position. Our crystallographic data suggest why a dG-AAF adduct blocks replication more strongly than does a dG-AF adduct and provide a possible explanation for frameshift mutagenesis during replication bypass of a dG-AAF adduct. The dG-AAF nucleoside adopts a syn conformation that facilitates the intercalation of its fluorene ring into a hydrophobic pocket on the surface of the fingers subdomain and locks the fingers in an open, inactive conformation. In contrast, the dG-AF base at the templating position is not well defined by the electron density, consistent with weak binding to the polymerase and a possible interchange of this adduct between the syn and anti conformations.


    Organizational Affiliation

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
DNA polymerase
A
698Enterobacteria phage T7Mutation(s): 0 
EC: 2.7.7.7, 3.1.11.-
Find proteins for P00581 (Enterobacteria phage T7)
Go to UniProtKB:  P00581
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
Thioredoxin 1
B
108Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: trxA (fipA, tsnC)
Find proteins for P0AA25 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AA25
Entity ID: 1
MoleculeChainsLengthOrganism
5'-D(*GP*GP*AP*GP*AP*GP*TP*GP*AP*TP*T*GP*GP*T*AP*GP*TP*GP*TP*GP*AP*(2DT))-3'C22N/A
Entity ID: 2
MoleculeChainsLengthOrganism
5'-D(*CP*CP*CP*(AFG)*AP*TP*CP*AP*CP*AP*CP*TP*AP*CP*CP*AP*AP*TP*CP*AP*CP*TP*CP*TP*CP*C)-3'D26N/A
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
AFG
Query on AFG
D
DNA LINKINGC23 H23 N6 O7 PDG
2DT
Query on 2DT
C
DNA LINKINGC10 H15 N2 O7 PDT
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.230 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 105.944α = 90.00
b = 213.559β = 90.00
c = 52.168γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
EPMRphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-10-26
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance