THE STRUCTURE OF THE NF-KAPPA-B P50-DNA-COMPLEX - A STARTING POINT FOR ANALYZING THE REL FAMILY

The Rel family comprises a group of structurally related, eukaryotic t ranscription factors. The similarity extends over about 300 amino acid residues, the Rel homology region, which is responsible for DNA bindi ng and dimerization. Two independently determined structures of homodi meric NF-kappa B p50 bound to DNA show the Rel homology regions and th e DNA target sites. The protein consists of two beta-barrel domains co nnected by a short linker. Five loops per monomer contact the DNA, Dif ferent half-site spacings in the two structures lead to different rela tive orientations of N- and C-terminal domains.