5VS0

Human DNA polymerase beta 8-oxoG:dC extension with dTTP after 80 s


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.202 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Time-Dependent Extension from an 8-Oxoguanine Lesion by Human DNA Polymerase Beta.

Reed, A.J.Suo, Z.

(2017) J. Am. Chem. Soc. 139: 9684-9690

  • DOI: 10.1021/jacs.7b05048
  • Primary Citation of Related Structures:  5VRW, 5VRX, 5VRY, 5VRZ, 5VS1, 5VS2, 5VS3, 5VS4

  • PubMed Abstract: 
  • The oxidative DNA lesion 7,8-dihydro-2'-deoxyguanine (8-oxoG) often occurs in double-stranded DNA and poses a threat to genomic integrity due to the ability of 8-oxoG to form stable Watson-Crick base pairs with deoxycytidine (8-oxoG:dC) and Hoogsteen ...

    The oxidative DNA lesion 7,8-dihydro-2'-deoxyguanine (8-oxoG) often occurs in double-stranded DNA and poses a threat to genomic integrity due to the ability of 8-oxoG to form stable Watson-Crick base pairs with deoxycytidine (8-oxoG:dC) and Hoogsteen base pairs with deoxyadenosine (8-oxoG:dA). In humans, short-patch base excision repair of 8-oxoG:dA base pairs requires human DNA polymerase β (hPolβ) to bypass 8-oxoG. Previously, we have shown hPolβ-catalyzed 8-oxoG bypass to exhibit low fidelity and identified a unique stacking interaction between the newly incorporated nucleotide (dCMP or dAMP) and the templating 8-oxoG. The effect of this stacking on the ability of hPolβ to extend from 8-oxoG during long-patch base excision repair was unknown. Here we report pre-steady-state kinetics and time-dependent crystal structures to demonstrate that extension from both 8-oxoG:dC and 8-oxoG:dA base pairs is 18- to 580-fold less efficient compared to 8-oxoG bypass and that extension from 8-oxoG:dC over 8-oxoG:dA is favored by 15-fold. The overall decrease in efficiency of extension relative to 8-oxoG bypass is due to an alternative nucleotide binding conformation in the precatalytic ternary structures (hPolβ·DNA·dNTP) for both extension contexts, wherein the incoming nucleotide is bound in either the canonical Watson-Crick base pair or a nonplanar base pair. In addition, the decreased stability of the ternary complex of 8-oxoG:dA extension results in further loss of efficiency when compared to 8-oxoG:dC extension. Therefore, we hypothesize that the inefficient extension from 8-oxoG:dA serves as a newly discovered fidelity checkpoint during base excision repair.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, The Ohio State Biochemistry Program, The Ohio State University , Columbus, Ohio 43210, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DNA polymerase beta
A
341Homo sapiensGene 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
DNA (5'-D(P*GP*TP*CP*GP*G)-3')D5synthetic construct
Entity ID: 3
MoleculeChainsLengthOrganism
DNA (5'-D(*CP*TP*GP*AP*TP*GP*CP*GP*CP*CP*T)-3')P11synthetic construct
Entity ID: 4
MoleculeChainsLengthOrganism
DNA (5'-D(*CP*CP*GP*AP*CP*AP*(8OG)P*GP*CP*GP*CP*AP*TP*CP*AP*G)-3')T16synthetic construct
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

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A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
MG
Query on MG

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A, P
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
IMD
Query on IMD

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A
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
 Ligand Interaction
PPV
Query on PPV

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A
PYROPHOSPHATE
H4 O7 P2
XPPKVPWEQAFLFU-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
8OG
Query on 8OG
T
DNA LINKINGC10 H14 N5 O8 PDG
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.202 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 50.600α = 90.00
b = 80.300β = 107.60
c = 55.400γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
XDSdata scaling
XSCALEdata scaling
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data

  • Deposited Date: 2017-05-11 
  • Released Date: 2017-07-19 
  • Deposition Author(s): Reed, A.J., Suo, Z.

Funding OrganizationCountryGrant Number
National Institutes of HealthUnited States--

Revision History 

  • Version 1.0: 2017-07-19
    Type: Initial release
  • Version 1.1: 2017-07-26
    Type: Database references
  • Version 1.2: 2017-11-22
    Type: Refinement description