Figure 1.

Green links change from one easily authored molecular scene to another. (a) For example, a user interested in hemoglobin visits the page of that name in Proteopedia (see [41]), which then loads with a slowly rotating crystal structure of hemoglobin in an interactive Jmol applet. (b) As the user reads that hemoglobin is a tetramer and that each of its subunits contains a heme prosthetic group, she or he can click on a green link in the corresponding text, eliciting a change in the hemoglobin in the Jmol applet, coloring each subunit a different color and displaying them in a smoothed trace of their α-carbon backbones, so that the hemes, colored in red, are easily visible. (c, d) While reading a sentence explaining that each heme contains an Fe²⁺ atom and clicking the appropriate green link, the user can watch the virtual hemoglobin molecule slowly rotate to a viewpoint that displays only a single heme, zoomed in, with its Fe²⁺ atom highlighted (c) or anchored to the protein (d). (e) When the user clicks on 'glutamic acid to a valine' he or she can see the specific point mutation in the hemoglobin molecule that causes sickle-cell anemia. Thus, text discussing and describing the structure and function is reinforced by immediate and specific three-dimensional visualization.