4R64

Binary complex crystal structure of E295K mutant of DNA polymerase Beta


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Substrate-induced DNA Polymerase beta Activation.

Beard, W.A.Shock, D.D.Batra, V.K.Prasad, R.Wilson, S.H.

(2014) J.Biol.Chem. 289: 31411-31422

  • DOI: 10.1074/jbc.M114.607432
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • DNA polymerases and substrates undergo conformational changes upon forming protein-ligand complexes. These conformational adjustments can hasten or deter DNA synthesis and influence substrate discrimination. From structural comparison of binary DNA a ...

    DNA polymerases and substrates undergo conformational changes upon forming protein-ligand complexes. These conformational adjustments can hasten or deter DNA synthesis and influence substrate discrimination. From structural comparison of binary DNA and ternary DNA-dNTP complexes of DNA polymerase β, several side chains have been implicated in facilitating formation of an active ternary complex poised for chemistry. Site-directed mutagenesis of these highly conserved residues (Asp-192, Arg-258, Phe-272, Glu-295, and Tyr-296) and kinetic characterization provides insight into the role these residues play during correct and incorrect insertion as well as their role in conformational activation. The catalytic efficiencies for correct nucleotide insertion for alanine mutants were wild type ∼ R258A > F272A ∼ Y296A > E295A > D192A. Because the efficiencies for incorrect insertion were affected to about the same extent for each mutant, the effects on fidelity were modest (<5-fold). The R258A mutant exhibited an increase in the single-turnover rate of correct nucleotide insertion. This suggests that the wild-type Arg-258 side chain generates a population of non-productive ternary complexes. Structures of binary and ternary substrate complexes of the R258A mutant and a mutant associated with gastric carcinomas, E295K, provide molecular insight into intermediate structural conformations not appreciated previously. Although the R258A mutant crystal structures were similar to wild-type enzyme, the open ternary complex structure of E295K indicates that Arg-258 stabilizes a non-productive conformation of the primer terminus that would decrease catalysis. Significantly, the open E295K ternary complex binds two metal ions indicating that metal binding cannot overcome the modified interactions that have interrupted the closure of the N-subdomain.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DNA polymerase beta
A
335Homo sapiensMutation(s): 1 
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
DNA (5'-D(*CP*CP*GP*AP*CP*AP*GP*CP*GP*CP*AP*TP*CP*AP*GP*C)-3')T16synthetic construct
Entity ID: 3
MoleculeChainsLengthOrganism
DNA (5'-D(*GP*CP*TP*GP*AP*TP*GP*CP*GP*C)-3')P10synthetic construct
Entity ID: 4
MoleculeChainsLengthOrganism
DNA (5'-D(P*GP*TP*CP*GP*G)-3')D5synthetic 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
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.190 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 53.525α = 90.00
b = 79.009β = 106.12
c = 54.505γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
DENZOdata reduction
SCALEPACKdata scaling
PHENIXrefinement
PHENIXphasing
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-10-08
    Type: Initial release
  • Version 1.1: 2014-10-15
    Type: Database references
  • Version 1.2: 2014-11-26
    Type: Database references
  • Version 1.3: 2017-11-22
    Type: Refinement description