2PUE

CRYSTAL STRUCTURE OF THE LACI FAMILY MEMBER, PURR, BOUND TO DNA: MINOR GROOVE BINDING BY ALPHA HELICES

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Observed: 0.175 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history. 


Literature

Structure-based redesign of corepressor specificity of the Escherichia coli purine repressor by substitution of residue 190.

Lu, F., Schumacher, M.A., Arvidson, D.N., Haldimann, A., Wanner, B.L., Zalkin, H., Brennan, R.G.

(1998) Biochemistry 37: 971-982

  • DOI: 10.1021/bi971942s
  • Primary Citation of Related Structures:  
    2PUE, 2PUF, 2PUG

  • PubMed Abstract: 

    • Guanine or hypoxanthine, physiological corepressors of the Escherichia coli purine repressor (PurR), promote formation of the ternary PurR-corepressor-operator DNA complex that functions to repress pur operon gene expression. Structure-based predictions on the importance of Arg190 in determining 6-oxopurine specificity and corepressor binding affinity were tested by mutagenesis, analysis of in vivo function, and in vitro corepressor binding measurements ...

    Guanine or hypoxanthine, physiological corepressors of the Escherichia coli purine repressor (PurR), promote formation of the ternary PurR-corepressor-operator DNA complex that functions to repress pur operon gene expression. Structure-based predictions on the importance of Arg190 in determining 6-oxopurine specificity and corepressor binding affinity were tested by mutagenesis, analysis of in vivo function, and in vitro corepressor binding measurements. Replacements of Arg190 with Ala or Gln resulted in functional repressors in which binding of guanine and hypoxanthine was retained but specificity was relaxed to permit binding of adenine. X-ray structures were determined for ternary complexes of mutant repressors with purines (adenine, guanine, hypoxanthine, and 6-methylpurine) and operator DNA. These structures indicate that R190A binds guanine, hypoxanthine, and adenine with nearly equal, albeit reduced, affinity in large part because of a newly made compensatory hydrogen bond between the rotated hydroxyl side chain of Ser124 and the exocyclic 6 positions of the purines. Through direct and water-mediated contacts, the R190Q protein binds adenine with a nearly 75-fold higher affinity than the wild type repressor while maintaining wild type affinity for guanine and hypoxanthine. The results establish at the atomic level the basis for the critical role of Arg190 in the recognition of the exocyclic 6 position of its purine corepressors and the successful redesign of corepressor specificity.

    Related Citations: 
    • Crystal Structure of LacI Member, PurR, Bound to DNA: Minor Groove Binding by Alpha Helices
      Schumacher, M.A., Choi, K.Y., Zalkin, H., Brennan, R.G.
      (1994) Science 266: 763
    Organizational Affiliation: 

    Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907-1153, USA.



Macromolecules

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(by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
PROTEIN (PURINE REPRESSOR )B [auth A]340Escherichia coliMutation(s): 1 
Gene Names: purR
UniProt
Find proteins for P0ACP7 (Escherichia coli (strain K12))
Explore P0ACP7 
Go to UniProtKB:  P0ACP7
Protein Feature View
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  • Reference Sequence
  • Find similar nucleic acids by:  Sequence   |   Structure
    • Entity ID: 1
    MoleculeChainsLengthOrganismImage
    DNA (5'-D(*TP*AP*CP*GP*CP*AP*AP*AP*CP*GP*TP*TP*TP*GP*CP*GP*T )-3')A [auth B]17N/A
    Protein Feature View
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    • Reference Sequence
    Small Molecules
    Ligands 1 Unique
    IDChainsName / Formula / InChI Key2D Diagram3D Interactions
    ADE
    Query on ADE
    Download Ideal Coordinates CCD File 
    		C [auth A]ADENINE
    C5 H5 N5
    GFFGJBXGBJISGV-UHFFFAOYSA-N    		 Ligand Interaction
    Binding Affinity Annotations 
    IDSourceBinding Affinity
    DNA PDBBind:  2PUE Kd: 3.30e+4 (nM) from 1 assay(s)
    Experimental Data & Validation

    Experimental Data

    • Method: X-RAY DIFFRACTION
    • Resolution: 2.70 Å
    • R-Value Observed: 0.175 
    • Space Group: C 2 2 21
    Unit Cell:
    Length ( Å )Angle ( ˚ )
    a = 175.81α = 90
    b = 95.17β = 90
    c = 81.31γ = 90
    Software Package:
    Software NamePurpose
    TNTrefinement

    Structure Validation

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    View more in-depth experimental data

    Entry History 

    Deposition Data

    Revision History  (Full details and data files)

    • Version 1.0: 1998-05-06
      Type: Initial release
    • Version 1.1: 2008-05-22
      Changes: Version format compliance
    • Version 1.2: 2011-07-13
      Changes: Version format compliance
    • Version 1.3: 2018-04-04
      Changes: Data collection