6V8U

Kaiso (ZBTB33) zinc finger DNA binding domain in complex with a modified Kaiso binding sequence (KBS)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.175 

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
  • Structures With Same Primary Citation

  • 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 motif ...

    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

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Transcriptional regulator Kaiso
A
134Homo sapiensMutation(s): 0 
Gene Names: ZBTB33KAISOZNF348
Find proteins for Q86T24 (Homo sapiens)
Go to UniProtKB:  Q86T24
NIH Common Fund Data Resources
PHAROS  Q86T24
  • Find similar nucleic acids by: Sequence   |   Structure
Entity ID: 2
MoleculeChainsLengthOrganism
DNA (5'-D(*TP*GP*CP*TP*TP*CP*GP*TP*GP*CP*CP*AP*AP*TP*AP*AP*CP*G)-3')D18Homo sapiens
  • Find similar nucleic acids by: Sequence   |   Structure
Entity ID: 3
MoleculeChainsLengthOrganism
DNA (5'-D(*CP*GP*TP*TP*AP*TP*TP*GP*GP*CP*AP*CP*GP*AP*AP*GP*CP*A)-3')E18Homo sapiens
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
NA
Query on NA

Download CCD File 
E
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.175 
  • Space Group: C 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.142α = 90
b = 183.624β = 90
c = 97.755γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United States--

Revision History 

  • Version 1.0: 2020-04-15
    Type: Initial release
  • Version 1.1: 2020-05-13
    Changes: Database references