I know that plasmids can be present in a coiled form, which keeps the DNA strands together when they degenerate, by forming catenases.
I was wondering, however, whether it has been documented to naturally happen or if anybody has ever successfully created a Möbius-strip plasmid. Technically, such a structure could readily form from a single circular strand of DNA, but the literature, as far as I have searched, has remained silent.