STRUCTURAL FEATURES INVOLVED IN THE FORMATION OF A COMPLEX BETWEEN THE MONOMERIC OR THE DIMERIC FORM OF THE REV-ERB-BETA DNA-BINDING DOMAINAND ITS DNA REACTIVE SITES

The nuclear receptor superfamily comprises a group of transcriptional regulators involved in a wide variety of physiological responses. Rev- erb beta is a member of a growing subfamily of orphan nuclear receptor s that bind DNA with high affinity either as monomers or as hetero- or homodimers. DNA bending assays, high-resolution footprinting, molecul ar modeling, and site-directed mutagenesis were used to analyze the st ructural features of the interaction between the DNA-binding domain (D BD) of the nuclear receptor Rev-erb beta and its DNA target sites. The results obtained point to the involvement of a carboxyl-terminal sequ ence adjacent to the second zinc finger of the Rev-erb beta DBD in pro tein-DNA interaction as a monomer or in protein-DNA and protein-protei n interactions as a homodimer. They also provide insight about the ami no acid residues directly involved in protein-protein contacts.