he central axis of the famous DNA double helix is
often topologically constrained or even circular.
The topology of this axis can influence which
proteins interact with the underlying DNA. Subsequently, in all cells there are
proteins whose primary function is to change the DNA axis
topology -- for example converting a torus link into an unknot.
Additionally, there are several protein families that change the axis
topology as a by-product of their interaction with DNA.

This talk will describe typical DNA conformations, and the families of
proteins that change these conformations. I'll present a few examples
illustrating how 3-manifold topology has been useful in understanding certain
DNA-protein interactions, and discuss the most common topological techniques
used to attack these problems.