I am a mathematics grad student researching knot theory, and I've recently discovered that there is a connection between knot theory and DNA structure (if I understand correctly, when DNA strands repackage, they do it in a way similar to what is known as Skein relations in knot theory, therefore tools from knot theory can be applied to DNA research).
The problem is that I have almost no background in biology, therefore it is difficult for me to understand how exactly DNA repackages and what happens on the molecular level.
Could anyone suggest some basic (and preferably not too long) text which gives an introduction to the structure of DNA? I have some basic background in organic chemistry, and I am not really looking to understand the topic thoroughly, just to visualize what's going on so I could see the analogy to the mathematical theory.
Thanks in advance!