1ZYQ

T7 DNA polymerase in complex with 8oG and incoming ddATP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.224 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A lysine residue in the fingers subdomain of t7 DNA polymerase modulates the miscoding potential of 8-oxo-7,8-dihydroguanosine.

Brieba, L.G.Kokoska, R.J.Bebenek, K.Kunkel, T.A.Ellenberger, T.

(2005) Structure 13: 1653-1659

  • DOI: 10.1016/j.str.2005.07.020

  • PubMed Abstract: 
  • 8-oxo-7,8-dihydroguanosine (8oG) is a highly mutagenic DNA lesion that stably pairs with adenosine, forming 8oG(syn).dA(anti) Hoogsteen base pairs. DNA polymerases show different propensities to insert dCMP or dAMP opposite 8oG, but the molecular mec ...

    8-oxo-7,8-dihydroguanosine (8oG) is a highly mutagenic DNA lesion that stably pairs with adenosine, forming 8oG(syn).dA(anti) Hoogsteen base pairs. DNA polymerases show different propensities to insert dCMP or dAMP opposite 8oG, but the molecular mechanisms that determine faithful or mutagenic bypass are poorly understood. Here, we report kinetic and structural data providing evidence that, in T7 DNA polymerase, residue Lys536 is responsible for attenuating the miscoding potential of 8oG. The Lys536Ala polymerase shows a significant increase in mutagenic 8oG bypass versus wild-type polymerase, and a crystal structure of the Lys536Ala mutant reveals a closed complex with an 8oG(syn).dATP mismatch in the polymerase active site, in contrast to the unproductive, open complex previously obtained by using wild-type polymerase. We propose that Lys536 acts as a steric and/or electrostatic filter that attenuates the miscoding potential of 8oG by normally interfering with the binding of 8oG in a syn conformation that pairs with dATP.


    Organizational Affiliation

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Massachusetts 02115, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
DNA polymerase
A
698Enterobacteria phage T7Mutation(s): 1 
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(*CP*GP*AP*AP*AP*AP*CP*GP*AP*CP*GP*GP*CP*CP*AP*GP*TP*GP*CP*CP*AP*(DDG))-3'P22N/A
Entity ID: 2
MoleculeChainsLengthOrganism
5'-D(*CP*CP*CP*(8OG)P*CP*TP*GP*GP*CP*AP*CP*TP*GP*GP*CP*CP*GP*TP*CP*GP*TP*TP*TP*TP*CP*G)-3'T26N/A
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
DAD
Query on DAD

Download SDF File 
Download CCD File 
A
2',3'-DIDEOXYADENOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O11 P3
OAKPWEUQDVLTCN-RQJHMYQMSA-N
 Ligand Interaction
MG
Query on MG

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Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
DDG
Query on DDG
P
DNA LINKINGC10 H14 N5 O6 PDG
8OG
Query on 8OG
T
DNA LINKINGC10 H14 N5 O8 PDG
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.224 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 106.148α = 90.00
b = 213.007β = 90.00
c = 52.990γ = 90.00
Software Package:
Software NamePurpose
CNSphasing
CNSrefinement
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-11-22
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance