%0 Journal Article
%T Structural and biochemical analyses of the nuclear IκBζ protein in complex with the NF-κB p50 homodimer.
%A Zhu N
%A Rogers WE
%A Heidary DK
%A Huxford T
%J Genes Dev
%V 38
%N 11
%D 2024 Jul 19
%M 38960718
%F 12.89
%R 10.1101/gad.351892.124
%X As part of the efforts to understand nuclear IκB function in NF-κB-dependent gene expression, we report an X-ray crystal structure of the IκBζ ankyrin repeat domain in complex with the dimerization domain of the NF-κB p50 homodimer. IκBζ possesses an N-terminal α helix that conveys domain folding stability. Affinity and specificity of the complex depend on a small portion of p50 at the nuclear localization signal. The model suggests that only one p50 subunit supports binding with IκBζ, and biochemical experiments confirm that IκBζ associates with DNA-bound NF-κB p50:RelA heterodimers. Comparisons of IκBζ:p50 and p50:κB DNA complex crystallographic models indicate that structural rearrangement is necessary for ternary complex formation of IκBζ and p50 with DNA.