This is a "sequence walker". The row of letters contains only a, c, g and t, and represent a DNA sequence of bases. The letters at each position don't change - watch it carefully to confirm this. The colored part is the "walker" for the Fis protein. It shows how the protein and DNA would react to each other if the protein were at different positions. Letters that go up mean they like being together there, down means the protein and DNA don't like that combination. The sine wave represents the twist of B-form DNA, with major grooves pointing toward the protein being the crest and minor grooves pointing away from the protein being the trough. The heights are measured in bits of information which is the only method that makes the heights additive. Don't be fooled by other methods that won't let you compare different positions on a single universal scale!
The movie was made using gifmerge. It used to bomb netscape and hang explorer because the gif images varied in size. When I normalized the images, the problem was solved.
origin: 1996 Oct 18
updated: 2011 Aug 24