The nucleosome unwrapping free energy landscape defines distinct regions of transcription factor accessibility and kinetics.

ABSTRACT: Transcription factors (TF) require access to target sites within nucleosomes to initiate transcription. The target site position within the nucleosome significantly influences TF occupancy, but how is not quantitatively understood. Using ensemble and single-molecule fluorescence measurements, we investigated the targeting and occupancy of the transcription factor, Gal4, at different positions within the nucleosome. We observe a dramatic decrease in TF occupancy to sites extending past 30 base pairs (bp) into the nucleosome which cannot be explained by changes in the TF dissociation rate or binding site orientation. Instead, the nucleosome unwrapping free energy landscape is the primary determinant of Gal4 occupancy by reducing the Gal4 binding rate. The unwrapping free energy landscape def

SUBMITTER: Donovan BT 

PROVIDER: S-EPMC9943653 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature