UHRF1 and UHRF2 are multiple-domain epigenetic proteins that share a high degree of sequence similarity. These proteins play a very important role in histone modification and DNA methylation. Although both proteins contain a TTD and a PHD domain, the TTD domain of UHRF2 contains a unique ~35 amino acid long region that is highly basic called the “stretch”. This region was analyzed for the possibility of being a disordered region using the Sypro Orange Thermofluor assay. We found that UHRF2 TTD-PHD has a lower melting temperature than UHRF2 TTD-PHD without the stretch. It was also found that at higher salt concentrations, the melting temperature of UHRF2 TTD-PHD increases, likely due to the disordered “stretch” region becoming stabilized. This data provides support towards the model that the stretch region is disordered and regulates protein stability.
