Crystallization and preliminary X-ray analysis of a complex of the FOXO1 and Ets1 DNA-binding domains and DNA

Area of Science:

• Molecular Biology
• Structural Biology
• Genetics

Background:

• Ets1 is a transcription factor in the Ets protein family, regulating genes in cellular processes like proliferation and apoptosis.
• FOXO1, a forkhead-box protein, controls genes involved in metabolism, cell survival, and DNA damage responses.
• Both Ets1 and FOXO1 play roles in cellular proliferation, differentiation, and transformation.

Purpose of the Study:

• To determine the crystal structure of Ets1 and FOXO1 DNA-binding domains in complex with a composite DNA binding site.
• To elucidate the structural basis for the recognition of the FOX:ETS motif by these transcription factors.
• To understand the role of the FOX:ETS motif in regulating endothelial cell-specific genes.

Main Methods:

• Crystallization of Ets1 and FOXO1 DNA-binding domains (DBDs) complexed with a DNA containing a composite forkhead binding site (AATAACA) and an ETS site (GGAA).
• The sitting-drop vapor-diffusion method was employed for crystal growth.
• X-ray diffraction data were collected to a resolution of 2.2 Å.

Main Results:

• Crystals of the Ets1 and FOXO1 DBDs bound to the FOX:ETS DNA motif were obtained.
• The crystals belonged to space group C222(1) with specific unit-cell parameters.
• The structural data provide insights into how these transcription factors interact with the composite DNA motif.

Conclusions:

• The study provides the first structural characterization of Ets1 and FOXO1 bound to the FOX:ETS motif.
• This motif is a conserved regulatory element in endothelial cell-specific genes like Vegfr2 and Tie2.
• The structural insights are crucial for understanding the transcriptional regulation of key genes in endothelial cells.