Structural Insight into the DNA Binding Function of Transcription Factor ERF.

Area of Science:

• Molecular Biology
• Structural Biology
• Genetics

Background:

• ETS family transcription factors regulate human cell development; their deregulation causes developmental syndromes and cancers.
• ERF (ETS-related factor) is an ETS family repressor essential for osteogenesis and hematopoiesis.
• ERF functions as a tumor suppressor by counteracting oncogenic ETS fusions, but its structure and DNA binding remain unclear.

Purpose of the Study:

• To elucidate the structure and DNA-binding properties of the ERF protein's DNA-binding domain.
• To investigate the potential functional states of ERF in complex with DNA.

Main Methods:

• Determined crystal structures of the ERF DNA-binding domain complexed with DNA.
• Utilized sedimentation velocity analysis to study ERF assembly on DNA.
• Performed bioinformatic analysis of ERF binding loci across human genomes.

Main Results:

• Two crystal structures revealed ERF in a dimeric form and a unique tetrameric assembly.
• The tetrameric state involves two ERF dimers bound to tandem GGAA sites spaced by 7 bp, stabilized by disulfide bonds.
• Bioinformatic analysis confirmed enrichment of 7 bp spaced tandem sites in genomic ERF binding regions.

Conclusions:

• The study reveals the distinct dimeric and functional tetrameric structures of the ERF DNA-binding domain.
• The tetrameric assembly on tandem DNA sites represents a likely functional state of ERF in human cells.
• These findings provide structural insights into ERF's role in gene regulation, development, and tumor suppression.