3ISC

Binary complex of human DNA polymerase beta with an abasic site (THF) in the gapped DNA

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history. 

Literature

DNA polymerase beta substrate specificity: side chain modulation of the "A-rule".

Beard, W.A., Shock, D.D., Batra, V.K., Pedersen, L.C., Wilson, S.H.

(2009) J.Biol.Chem. 284: 31680-31689

  • DOI: 10.1074/jbc.M109.029843
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • Apurinic/apyrimidinic (AP) sites are continuously generated in genomic DNA. Left unrepaired, AP sites represent noninstructional premutagenic lesions that are impediments to DNA synthesis. When DNA polymerases encounter an AP site, they generally ins ...

    Apurinic/apyrimidinic (AP) sites are continuously generated in genomic DNA. Left unrepaired, AP sites represent noninstructional premutagenic lesions that are impediments to DNA synthesis. When DNA polymerases encounter an AP site, they generally insert dAMP. This preferential insertion is referred to as the A-rule. Crystallographic structures of DNA polymerase (pol) beta, a family X polymerase, with active site mismatched nascent base pairs indicate that the templating (i.e. coding) base is repositioned outside of the template binding pocket thereby diminishing interactions with the incorrect incoming nucleotide. This effectively produces an abasic site because the template pocket is devoid of an instructional base. However, the template pocket is not empty; an arginine residue (Arg-283) occupies the space vacated by the templating nucleotide. In this study, we analyze the kinetics of pol beta insertion opposite an AP site and show that the preferential incorporation of dAMP is lost with the R283A mutant. The crystallographic structures of pol beta bound to gapped DNA with an AP site analog (tertrahydrofuran) in the gap (binary complex) and with an incoming nonhydrolyzable dATP analog (ternary complex) were solved. These structures reveal that binding of the dATP analog induces a closed polymerase conformation, an unstable primer terminus, and an upstream shift of the templating residue even in the absence of a template base. Thus, dATP insertion opposite an abasic site and dATP misinsertions have common features.

    Organizational Affiliation: 

    Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 1
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: 2
MoleculeChainsLengthOrganism
5'-D(P*GP*TP*CP*GP*G)-3'D5synthetic construct
Entity ID: 3
MoleculeChainsLengthOrganism
5'-D(*GP*CP*TP*GP*AP*TP*GP*CP*GP*C)-3'P10synthetic construct
Entity ID: 4
MoleculeChainsLengthOrganism
5'-D(*CP*CP*GP*AP*CP*(3DR)P*GP*CP*GP*CP*AP*TP*CP*AP*GP*C)-3'T16synthetic construct
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA
Download SDF File 
Download CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
3DR
Query on 3DR
T
DNA LINKINGC5 H11 O6 P

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.186 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 54.410α = 90.00
b = 79.300β = 105.80
c = 54.950γ = 90.00
Software Package:
Software NamePurpose
CNSphasing
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots


View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-09-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2019-02-06
    Type: Data collection, Database references, Refinement description, Source and taxonomy, Structure summary