title: Common structural constituents confer I kappa B activity to NF-kappa B p105 and I kappa B/MAD-3.
abstract: The vertebrate NF-kappa B/c-rel inhibitors MAD-3/I kappa B alpha, I kappa B gamma/pdI and bcl-3 all share a conserved ankyrin repeat domain (ARD) consisting of six complete repeats, a short acidic motif and/or an incomplete seventh repeat. We present here a detailed analysis of the domain in p105/pdI and MAD-3/I kappa B involved in inhibition of DNA binding and in protein interaction with rel factors. We demonstrate that in both cases an acidic region and six ankyrin-like repeats are sufficient and required for protein interaction with the rel factors. However, for p105/pdI to achieve the high affinity needed to suppress DNA binding, an incomplete seventh repeat is required in addition. Both pdI and MAD-3 associate with rel proteins by forming heterotrimeric complexes, as shown by native gel analysis and by cross-linking. Furthermore, we demonstrate that deletion of only three amino acids in the first repeat converts the subunit specificity of the p105 ARD into that of MAD-3/I kappa B. We conclude that functionally the ARD in these molecules has a modular structure, with different subregions determining the specificity for the NF-kappa B subunits p50 and p65.
authors.affiliation: Max-Planck-Institut für Molekulare Genetik, Otto-Warburg-Laboratorium, Berline (Dahlem), Germany.
authors.forename: E N
authors.initials: EN
authors.lastname: Hatada
authors.forename: M
authors.initials: M
authors.lastname: Naumann
authors.forename: C
authors.initials: C
authors.lastname: Scheidereit
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017487:Ankyrins / Q000737:chemistry; D001665:Binding Sites; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D020672:I-kappa B Proteins; D008969:Molecular Sequence Data; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000737:chemistry / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D013329:Structure-Activity Relationship; D051841:Transcription Factor RelB; D014157:Transcription Factors; D014714:Vertebrates
chemical_list: D017487:Ankyrins; D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D011498:Protein Precursors; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D000072000:NF-KappaB Inhibitor alpha; D051841:Transcription Factor RelB; D004247:DNA