1X9M

T7 DNA polymerase in complex with an N-2-acetylaminofluorene-adducted DNA

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.213 

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*TP*GP*GP*TP*AP*GP*TP*GP*TP*GP*AP*(2DT))-3'C22N/A
Entity ID: 2
MoleculeChainsLengthOrganism
5'-D(*CP*CP*CP*(8FG)P*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
8FG
Query on 8FG
D
DNA LINKINGC25 H25 N6 O8 PDG
2DT
Query on 2DT
C
DNA LINKINGC10 H15 N2 O7 PDT
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.213 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 105.109α = 90.00
b = 212.308β = 90.00
c = 52.070γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
EPMRphasing
DENZOdata reduction

Structure Validation

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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