Nonhistone Proteins HMG ₁ and HMG ₂ Change the DNA Helical Structure

This is the authors' abstract. We don't add key points for this paper.

Two chromatin nonhistone proteins (from calf thymus) of the high mobility group, HMG1 and HMG2, reduce the linking number (topological winding number) of a circular DNA if the covalent closure of the DNA is carried out in their presence. This indicates that these proteins can either unwind the double helix, or induce a supercoiling of the DNA.