Interaction in vitro; protein produced as a recombinant fusion protein in bacterial system.

The chromo shadow domain of HP1b homodimerizes with a dimerization constant < 50 nM. This dimerization is inhibited in HP1b proteins that also contain the C-terminal extension domain (aa 161-240): Kd = 5.2 uM.

Analytical ultracentrifugation was used to assess the stability of HP1b homodimers.