You can mark a DNA molecule as circular by right-clicking its name in either the sequence view or the circular view. In the right-click menu you can also make a circular molecule linear. A circular molecule displayed in the normal sequence view, will have the sequence ends marked with a ».
The starting point of a circular sequence can be changed by:
make a selection starting at the position that you want to be the new starting point | right-click the selection | Move Starting Point to Selection Start
Note! This can only be done for sequence that have been marked as circular.