Heterodimeric dna

The insect ecdysteroid receptor consists of a heterodimer between EcR and the RXR-orthologue, USP. We addressed the question of whether this heterodimer, like all other RXR heterodimers, may be formed in the absence of ligand and whether ligand promotes dimerization. We found that C-terminal protein fragments that comprised the ligand binding, but not the DNA binding domain of EcR and USP and which were equipped with the activation or DNA binding region of GAL4, respectively, exhibit a weak ability to interact spontaneously with each other.

9p system191 01-06-2013 28 3   Download

Although allostery plays a central role in driving protein–DNA interac-tions, the physical basis of such cooperative behavior remains poorly understood. In the present study, using isothermal titration calorimetry in conjunction with site-directed mutagenesis, we provide evidence that an intricate network of energetically-coupled residues within the basic regions of the Jun-Fos heterodimeric transcription factor accounts for its allosteric binding to DNA.

15p cosis54 05-01-2013 34 3   Download

RNase H2 ofSaccharomyces cerevisiaeconsists of three essential subunits (Rnh201, Rnh202 and Rnh203) and plays a critical role in the removal of RNA incorporated in duplex DNA. In the present study, we purified indi-vidual subunits and heterodimeric subcomplexes to examine the assembly and biochemical function of subunits of RNase H2in vitro.

16p cosis54 08-12-2012 48 3   Download