2P9H

High resolution structure of the Lactose Repressor bound to IPTG


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.185 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural analysis of lac repressor bound to allosteric effectors.

Daber, R.Stayrook, S.Rosenberg, A.Lewis, M.

(2007) J.Mol.Biol. 370: 609-619

  • DOI: 10.1016/j.jmb.2007.04.028
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The lac operon is a model system for understanding how effector molecules regulate transcription and are necessary for allosteric transitions. The crystal structures of the lac repressor bound to inducer and anti-inducer molecules provide a model for ...

    The lac operon is a model system for understanding how effector molecules regulate transcription and are necessary for allosteric transitions. The crystal structures of the lac repressor bound to inducer and anti-inducer molecules provide a model for how these small molecules can modulate repressor function. The structures of the apo repressor and the repressor bound to effector molecules are compared in atomic detail. All effectors examined here bind to the repressor in the same location and are anchored to the repressor through hydrogen bonds to several hydroxyl groups of the sugar ring. Inducer molecules form a more extensive hydrogen-bonding network compared to anti-inducers and neutral effector molecules. The structures of these effector molecules suggest that the O6 hydroxyl on the galactoside is essential for establishing a water-mediated hydrogen bonding network that bridges the N-terminal and C-terminal sub-domains. The altered hydrogen bonding can account in part for the different structural conformations of the repressor, and is vital for the allosteric transition.


    Organizational Affiliation

    Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, 37th and Hamilton Walk, Philadelphia, PA 19104-6059, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Lactose operon repressor
A, B
269Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: lacI
Find proteins for P03023 (Escherichia coli (strain K12))
Go to UniProtKB:  P03023
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
IPT
Query on IPT

Download SDF File 
Download CCD File 
A, B
ISOPROPYL-1-BETA-D-THIOGALACTOSIDE
1-(ISOPROPYLTHIO)-BETA-GALACTOPYRANSIDE
C9 H18 O5 S
BPHPUYQFMNQIOC-NXRLNHOXSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.246 
  • R-Value Work: 0.185 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 77.125α = 90.00
b = 77.125β = 90.00
c = 210.583γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PHASERphasing
ADSCdata collection
DENZOdata reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2007-03-26 
  • Released Date: 2007-06-19 
  • Deposition Author(s): Daber, R.

Revision History 

  • Version 1.0: 2007-06-19
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance