2UGI

PROTEIN MIMICRY OF DNA FROM CRYSTAL STRUCTURES OF THE URACIL GLYCOSYLASE INHIBITOR PROTEIN AND ITS COMPLEX WITH ESCHERICHIA COLI URACIL-DNA GLYCOSYLASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.227 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Protein mimicry of DNA from crystal structures of the uracil-DNA glycosylase inhibitor protein and its complex with Escherichia coli uracil-DNA glycosylase

Putnam, C.D.Shroyer, M.J.Lundquist, A.J.Mol, C.D.Arvai, A.S.Mosbaugh, D.W.Tainer, J.A.

(1999) J.Mol.Biol. 287: 331-346

  • DOI: 10.1006/jmbi.1999.2605
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Uracil-DNA glycosylase (UDG), which is a critical enzyme in DNA base-excision repair that recognizes and removes uracil from DNA, is specifically and irreversably inhibited by the thermostable uracil-DNA glycosylase inhibitor protein (Ugi). A paradox ...

    Uracil-DNA glycosylase (UDG), which is a critical enzyme in DNA base-excision repair that recognizes and removes uracil from DNA, is specifically and irreversably inhibited by the thermostable uracil-DNA glycosylase inhibitor protein (Ugi). A paradox for the highly specific Ugi inhibition of UDG is how Ugi can successfully mimic DNA backbone interactions for UDG without resulting in significant cross-reactivity with numerous other enzymes that possess DNA backbone binding affinity. High-resolution X-ray crystal structures of Ugi both free and in complex with wild-type and the functionally defective His187Asp mutant Escherichia coli UDGs reveal the detailed molecular basis for duplex DNA backbone mimicry by Ugi. The overall shape and charge distribution of Ugi most closely resembles a midpoint in a trajectory between B-form DNA and the kinked DNA observed in UDG:DNA product complexes. Thus, Ugi targets the mechanism of uracil flipping by UDG and appears to be a transition-state mimic for UDG-flipping of uracil nucleotides from DNA. Essentially all the exquisite shape, electrostatic and hydrophobic complementarity for the high-affinity UDG-Ugi interaction is pre-existing, except for a key flip of the Ugi Gln19 carbonyl group and Glu20 side-chain, which is triggered by the formation of the complex. Conformational changes between unbound Ugi and Ugi complexed with UDG involve the beta-zipper structural motif, which we have named for the reversible pairing observed between intramolecular beta-strands. A similar beta-zipper is observed in the conversion between the open and closed forms of UDG. The combination of extremely high levels of pre-existing structural complementarity to DNA binding features specific to UDG with key local conformational changes in Ugi resolves the UDG-Ugi paradox and suggests a potentially general structural solution to the formation of very high affinity DNA enzyme-inhibitor complexes that avoid cross- reactivity.


    Organizational Affiliation

    Department of Molecular Biology, Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
URACIL-DNA GLYCOSYLASE INHIBITOR
A, B
84Bacillus phage PBS2Mutation(s): 0 
Gene Names: UGI
Find proteins for P14739 (Bacillus phage PBS2)
Go to UniProtKB:  P14739
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
IMD
Query on IMD

Download SDF File 
Download CCD File 
A
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.227 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 42.092α = 90.00
b = 59.387β = 90.00
c = 73.583γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
AMoREphasing
DENZOdata reduction
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-03-25
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance