Biophysical Society Thematic Meeting| Santa Cruz 2018

Genome Biophysics: Integrating Genomics and Biophysics to Understand Structural and Functional Aspects of Genomes

Poster Abstracts

9-POS Board 9 Eukaryotic Transcription Factors Can Track and Control Their Target Genes Using DNA Antennas Victor Munoz 1,2 ; Milagros Castellanos 2 ; 1 University of California Merced, Bioengineering, Merced, California, United States 2 IMDEA Nanoscience, Biophysics, Madrid, Madrid, Spain Eukaryotic transcription factors (TF) function by binding to short 6-10 bp DNA recognition sites located near each of their many target genes, which are scattered through vast genomes. Such process surmounts enormous specificity, efficiency and celerity challenges using a molecular mechanism that remains unknown. Combining biophysical experiments, theory and bioinformatics we dissected the interplay between the DNA-binding domain of Engrailed, a Drosophila TF, and the regulatory regions of its target genes. Remarkably, Engrailed binding affinity is greatly amplified by the DNA regions flanking the recognition site, which contain long tracts of degenerate binding-site repeats. Such DNA organization operates as an antenna that attracts TF molecules in a promiscuous exchange between myriads of weaker binding sites. The antenna ensures a local TF supply, enables gene tracking and fine control of basal site occupancy. This mechanism illuminates puzzling gene expression data, and suggests simple engineering strategies to control gene expression.

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