1EMJ

URACIL-DNA GLYCOSYLASE BOUND TO DNA CONTAINING A 4'-THIO-2'DEOXYURIDINE ANALOG PRODUCT


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.228 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Uracil-DNA glycosylase-DNA substrate and product structures: conformational strain promotes catalytic efficiency by coupled stereoelectronic effects.

Parikh, S.S.Walcher, G.Jones, G.D.Slupphaug, G.Krokan, H.E.Blackburn, G.M.Tainer, J.A.

(2000) Proc.Natl.Acad.Sci.USA 97: 5083-5088

  • Primary Citation of Related Structures:  1EMH

  • PubMed Abstract: 
  • Enzymatic transformations of macromolecular substrates such as DNA repair enzyme/DNA transformations are commonly interpreted primarily by active-site functional-group chemistry that ignores their extensive interfaces. Yet human uracil-DNA glycosylas ...

    Enzymatic transformations of macromolecular substrates such as DNA repair enzyme/DNA transformations are commonly interpreted primarily by active-site functional-group chemistry that ignores their extensive interfaces. Yet human uracil-DNA glycosylase (UDG), an archetypical enzyme that initiates DNA base-excision repair, efficiently excises the damaged base uracil resulting from cytosine deamination even when active-site functional groups are deleted by mutagenesis. The 1.8-A resolution substrate analogue and 2.0-A resolution cleaved product cocrystal structures of UDG bound to double-stranded DNA suggest enzyme-DNA substrate-binding energy from the macromolecular interface is funneled into catalytic power at the active site. The architecturally stabilized closing of UDG enforces distortions of the uracil and deoxyribose in the flipped-out nucleotide substrate that are relieved by glycosylic bond cleavage in the product complex. This experimentally defined substrate stereochemistry implies the enzyme alters the orientation of three orthogonal electron orbitals to favor electron transpositions for glycosylic bond cleavage. By revealing the coupling of this anomeric effect to a delocalization of the glycosylic bond electrons into the uracil aromatic system, this structurally implicated mechanism resolves apparent paradoxes concerning the transpositions of electrons among orthogonal orbitals and the retention of catalytic efficiency despite mutational removal of active-site functional groups. These UDG/DNA structures and their implied dissociative excision chemistry suggest biology favors a chemistry for base-excision repair initiation that optimizes pathway coordination by product binding to avoid the release of cytotoxic and mutagenic intermediates. Similar excision chemistry may apply to other biological reaction pathways requiring the coordination of complex multistep chemical transformations.


    Related Citations: 
    • Base excision repair initiation revealed by crystal structures and binding kinetics of human uracil-DNA glycosylase with DNA
      Parikh, S.S.,Mol, C.D.,Slupphaug, G.,Krokan, H.E.,Tainer, J.A.
      (1998) Embo J. 17: 5214


    Organizational Affiliation

    Skaggs Institute for Chemical Biology and the Department of Molecular Biology, MB-4, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037-1027, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
URACIL-DNA GLYCOSYLASE
A
223Homo sapiensGene Names: UNG (DGU, UNG1, UNG15)
EC: 3.2.2.27
Find proteins for P13051 (Homo sapiens)
Go to Gene View: UNG
Go to UniProtKB:  P13051
Entity ID: 1
MoleculeChainsLengthOrganism
DNA (5'-D(*TP*GP*TP*(ASU)P*AP*TP*CP*TP*T)-3')B9N/A
Entity ID: 2
MoleculeChainsLengthOrganism
DNA (5'-D(*AP*AP*AP*GP*AP*TP*AP*AP*CP*A)-3')C10N/A
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
URA
Query on URA

Download SDF File 
Download CCD File 
A
URACIL
C4 H4 N2 O2
ISAKRJDGNUQOIC-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
ASU
Query on ASU
B
DNA LINKINGC5 H11 O6 P S

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.228 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 48.554α = 90.00
b = 64.853β = 90.00
c = 96.010γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
MAR345data collection
SCALEPACKdata scaling
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-05-16
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Refinement description