ZOOM MODE Mode to zoom the displayed secondary structure.
HELIX MODE Mode to build and destroy helix regions.
Left mouse button converts the clicked loop region into a helix region (if possible).
Right mouse button removes the clicked helix region.
Hint: If you display SAI: HELIX it's easy to detect the helix
SET ROOT MODE
Left click on a loop which should be the fixpoint of your secondary structure. The root loop will not move if you create or remove helix region nor if you rotate branches of the secondary structure.
Right click onto a loop or helix to reset the angles between it and its neighbours.
Left click onto a helix or loop to rotate it (and its complete substructure).
Use right click to rotate w/o rotating the substructure.
Left click and drag a helix or loop to stretch or compress its size.
Right click to remove size constraints.
Left click on a helix or loop and edit its size constraints manually.
SET CURSOR MODE
Left click on a base character to set the cursor position in the primary structure editor.
PROBE INFO MODE
Left click on