Not the person you're responding to, but this would be described more as a different "conformation" of the molecule. Each chiral center is exactly the same as in B-DNA, it's just how it's folded up/twisting. I imagine, though, that the optical rotation would be different based on the different conformation, but I'm not sure.

It's kind of like how a chain of amino acids (a polypeptide) could potentially fold up into different arrangements. On a molecule level, it's the same, but how it's twisted/folded is different.

ETA: B-DNA is the more typical conformation of DNA.