Nucleosome configurations of “activated” promoters.

<p><i>PHO5</i> gene molecules are aligned with their 3′ forked end on the top. A bent arrow indicates the position of the transcription start site. The inferred promoter nucleosome configuration is shown in the left lower corner of each image, where the promoter is represented by a box and occupied nucleosome positions by black dots. The top position represents N-1, the middle position N-2, and the bottom position N-3. Nucleosome configurations representing all eight possible combinations of occupied and unoccupied positions N-1 to N-3 were observable. Bars indicate 100 nm. (See also <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001621#pbio.1001621.s001" target="_blank">Figure S1</a>).