1T3N

Structure of the catalytic core of DNA polymerase Iota in complex with DNA and dTTP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.265 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Replication by human DNA polymerase-iota occurs by Hoogsteen base-pairing.

Nair, D.T.Johnson, R.E.Prakash, S.Prakash, L.Aggarwal, A.K.

(2004) Nature 430: 377-380

  • DOI: 10.1038/nature02692
  • Also Cited By: 1ZET

  • PubMed Abstract: 
  • Almost all DNA polymerases show a strong preference for incorporating the nucleotide that forms the correct Watson-Crick base pair with the template base. In addition, the catalytic efficiencies with which any given polymerase forms the four possible ...

    Almost all DNA polymerases show a strong preference for incorporating the nucleotide that forms the correct Watson-Crick base pair with the template base. In addition, the catalytic efficiencies with which any given polymerase forms the four possible correct base pairs are roughly the same. Human DNA polymerase-iota (hPoliota), a member of the Y family of DNA polymerases, is an exception to these rules. hPoliota incorporates the correct nucleotide opposite a template adenine with a several hundred to several thousand fold greater efficiency than it incorporates the correct nucleotide opposite a template thymine, whereas its efficiency for correct nucleotide incorporation opposite a template guanine or cytosine is intermediate between these two extremes. Here we present the crystal structure of hPoliota bound to a template primer and an incoming nucleotide. The structure reveals a polymerase that is 'specialized' for Hoogsteen base-pairing, whereby the templating base is driven to the syn conformation. Hoogsteen base-pairing offers a basis for the varied efficiencies and fidelities of hPoliota opposite different template bases, and it provides an elegant mechanism for promoting replication through minor-groove purine adducts that interfere with replication.


    Organizational Affiliation

    Structural Biology Program, Department of Physiology and Biophysics, Mount Sinai School of Medicine, Box 1677, 1425 Madison Avenue, New York, New York 10029, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
polymerase (DNA directed) iota
A, B
388Homo sapiensGene Names: POLI (RAD30B)
EC: 2.7.7.7
Find proteins for Q9UNA4 (Homo sapiens)
Go to Gene View: POLI
Go to UniProtKB:  Q9UNA4
Entity ID: 1
MoleculeChainsLengthOrganism
Template DNA strandT14N/A
Entity ID: 2
MoleculeChainsLengthOrganism
Primer DNA strandP13N/A
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TTP
Query on TTP

Download SDF File 
Download CCD File 
B
THYMIDINE-5'-TRIPHOSPHATE
C10 H17 N2 O14 P3
NHVNXKFIZYSCEB-XLPZGREQSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
DOC
Query on DOC
P
DNA LINKINGC9 H14 N3 O6 PDC
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.265 
  • Space Group: P 65
Unit Cell:
Length (Å)Angle (°)
a = 98.831α = 90.00
b = 98.831β = 90.00
c = 202.755γ = 120.00
Software Package:
Software NamePurpose
HKL-2000data collection
SCALEPACKdata scaling
SOLVEphasing
HKL-2000data reduction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-07-20
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2015-09-09
    Type: Other