7TXC image
Entry Detail
PDB ID:
7TXC
Keywords:
DNA BINDING PROTEIN/DNA
Title:
HIC2 zinc finger domain in complex with the DNA binding motif-2 of the BCL11A enhancer
Biological Source:
Source Organism:
Homo sapiens
Host Organism:
Escherichia coli BL21(DE3)
PDB Version:
Deposition Date:
2022-02-08
Release Date:
2022-06-01
Method Details:
Experimental Method:
X-RAY DIFFRACTION
Resolution:
3.04 Å
R-Value Free:
0.20
R-Value Work:
0.19
R-Value Observed:
0.19
Space Group:
P 31 2 1
7TXC validation report
Macromolecular Entities
Polymer Type:polydeoxyribonucleotide
Description:DNA (5'-D(*AP*GP*AP*TP*AP*AP*TP*GP*CP*CP*AP*AP*CP*AP*GP*T)-3')
Chain IDs:A
Chain Length:16
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polydeoxyribonucleotide
Description:DNA (5'-D(*AP*CP*TP*GP*TP*TP*GP*GP*CP*AP*TP*TP*AP*TP*CP*T)-3')
Chain IDs:B
Chain Length:16
Number of Molecules:1
Biological Source:Homo sapiens
Protein Blast
Polymer Type:polypeptide(L)
Description:Hypermethylated in cancer 2 protein
Chain IDs:C (auth: E)
Chain Length:118
Number of Molecules:1
Biological Source:Homo sapiens
UniProt ID:Q96JB3 Pfam ID:PF00096
Ligand Molecules
ZN
Primary Citation
HIC2 controls developmental hemoglobin switching by repressing BCL11A transcription.
Nat.Genet. 54 1417 1426 (2022)
PMID: 35941187 DOI: 10.1038/s41588-022-01152-6

Abstact

The fetal-to-adult switch in hemoglobin production is a model of developmental gene control with relevance to the treatment of hemoglobinopathies. The expression of transcription factor BCL11A, which represses fetal β-type globin (HBG) genes in adult erythroid cells, is predominantly controlled at the transcriptional level but the underlying mechanism is unclear. We identify HIC2 as a repressor of BCL11A transcription. HIC2 and BCL11A are reciprocally expressed during development. Forced expression of HIC2 in adult erythroid cells inhibits BCL11A transcription and induces HBG expression. HIC2 binds to erythroid BCL11A enhancers to reduce chromatin accessibility and binding of transcription factor GATA1, diminishing enhancer activity and enhancer-promoter contacts. DNA-binding and crystallography studies reveal direct steric hindrance as one mechanism by which HIC2 inhibits GATA1 binding at a critical BCL11A enhancer. Conversely, loss of HIC2 in fetal erythroblasts increases enhancer accessibility, GATA1 binding and BCL11A transcription. HIC2 emerges as an evolutionarily conserved regulator of hemoglobin switching via developmental control of BCL11A.

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Primary Citation of related structures
7TXC