To show the secondary view of an already open sequence, click the Show Secondary Structure 2D View () button at the bottom of the sequence view.
If the sequence is not open, click Show () and select Secondary Structure 2D View ().
This will open a view similar to the one shown in figure 26.9.
Like the normal sequence view, you can use Zoom in () and Zoom out (). Zooming in will reveal the residues of the structure as shown in figure 26.9. For large structures, zooming out will give you an overview of the whole structure.