6DFC

Kaiso (ZBTB33) zinc finger DNA binding domain in complex with the specific Kaiso binding sequence (KBS) with a T-to-U substitution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.187 
  • R-Value Observed: 0.189 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

A conformational switch in the zinc finger protein Kaiso mediates differential readout of specific and methylated DNA sequences.

Nikolova, E.N.Stanfield, R.L.Dyson, H.J.Wright, P.E.

(2020) Biochemistry 

  • DOI: 10.1021/acs.biochem.0c00253
  • Primary Citation of Related Structures:  
    6DF5, 6DFA, 6DFC, 6DFB, 6DF9, 6DF8, 6V8U

  • PubMed Abstract: 
  • Recognition of the epigenetic mark 5-methylcytosine (mC) at CpG sites in DNA has emerged as a novel function of many eukaryotic transcription factors (TFs). It remains unclear why the sequence specificity of these TFs differs for CpG-methylated motifs and consensus motifs ...

    Recognition of the epigenetic mark 5-methylcytosine (mC) at CpG sites in DNA has emerged as a novel function of many eukaryotic transcription factors (TFs). It remains unclear why the sequence specificity of these TFs differs for CpG-methylated motifs and consensus motifs. Here, we dissect the structural and dynamic basis for this differential DNA binding specificity in the human zinc finger TF Kaiso, which exhibits high affinity for two consecutive mCpG sites in variable contexts and also for a longer, sequence-specific Kaiso binding site (KBS). By integrating structural analysis and DNA binding studies with targeted protein mutagenesis and nucleotide substitutions, we identify distinct mechanisms for readout of methylated and KBS motifs by Kaiso. We show that a key glutamate residue (E535), critical for mCpG site recognition, adopts different conformations in complexes with specific and methylated DNA. These conformational differences, together with intrinsic variations in DNA flexibility and/or solvation at TpG versus mCpG sites, contribute to the different DNA affinity and sequence specificity. With methylated DNA, multiple direct contacts between E535 and the 5' mCpG site dominate the binding affinity, allowing for tolerance of different flanking DNA sequences. With KBS, Kaiso employs E535 as part of an indirect screen of the 5' flanking sequence, relying on key tyrosine-DNA interactions to stabilize an optimal DNA conformation and select against noncognate sites. These findings demonstrate how TFs use conformational adaptation and exploit variations in DNA flexibility to achieve distinct DNA readout outcomes and target a greater variety of regulatory and epigenetic sites than previously appreciated.


    Organizational Affiliation

    Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States.



Macromolecules

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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Transcriptional regulator KaisoA134Homo sapiensMutation(s): 0 
Gene Names: ZBTB33KAISOZNF348
UniProt & NIH Common Fund Data Resources
Find proteins for Q86T24 (Homo sapiens)
Explore Q86T24 
Go to UniProtKB:  Q86T24
PHAROS:  Q86T24
Protein Feature View
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  • Reference Sequence
  • Find similar nucleic acids by:  Sequence   |   Structure
  • Entity ID: 2
    MoleculeChainsLengthOrganismImage
    DNA (5'-D(*TP*GP*CP*TP*TP*CP*UP*TP*GP*CP*CP*AP*AP*TP*AP*AP*CP*G)-3')B [auth D]18Homo sapiens
    Protein Feature View
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    • Reference Sequence
    • Find similar nucleic acids by:  Sequence   |   Structure
    • Entity ID: 3
      MoleculeChainsLengthOrganismImage
      DNA (5'-D(*CP*GP*TP*TP*AP*TP*TP*GP*GP*CP*AP*AP*GP*AP*AP*GP*CP*A)-3')C [auth E]18Homo sapiens
      Protein Feature View
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      • Reference Sequence
      Small Molecules
      Ligands 2 Unique
      IDChainsName / Formula / InChI Key2D Diagram3D Interactions
      ZN
      Query on ZN

      Download Ideal Coordinates CCD File 
      D [auth A], E [auth A], F [auth A]ZINC ION
      Zn
      PTFCDOFLOPIGGS-UHFFFAOYSA-N
       Ligand Interaction
      CL
      Query on CL

      Download Ideal Coordinates CCD File 
      G [auth A]CHLORIDE ION
      Cl
      VEXZGXHMUGYJMC-UHFFFAOYSA-M
       Ligand Interaction
      Experimental Data & Validation

      Experimental Data

      • Method: X-RAY DIFFRACTION
      • Resolution: 1.85 Å
      • R-Value Free: 0.208 
      • R-Value Work: 0.187 
      • R-Value Observed: 0.189 
      • Space Group: C 2 2 2
      Unit Cell:
      Length ( Å )Angle ( ˚ )
      a = 44.24α = 90
      b = 184.451β = 90
      c = 104.705γ = 90
      Software Package:
      Software NamePurpose
      PHENIXrefinement
      HKL-2000data reduction
      HKL-2000data scaling
      PHENIXphasing

      Structure Validation

      View Full Validation Report




      Entry History 

      Deposition Data

      Revision History  (Full details and data files)

      • Version 1.0: 2019-05-22
        Type: Initial release
      • Version 1.1: 2020-05-13
        Changes: Database references