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Updated: Jun 16, 2026

A Guide to Production, Crystallization, and Structure Determination of Human IKK1/α
Published on: November 2, 2018
Solution structure of the KIX domain of CBP bound to the transactivation domain of CREB: a model for
I Radhakrishnan1, G C Pérez-Alvarado, D Parker
1Department of Molecular Biology, and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
Abstract:
The nuclear factor CREB activates transcription of target genes in part through direct interactions with the KIX domain of the coactivator CBP in a phosphorylation-dependent manner. The solution structure of the complex formed by the phosphorylated kinase-inducible domain (pKID) of CREB with KIX reveals that pKID undergoes a coil-->helix folding transition upon binding to KIX, forming two alpha helices. The amphipathic helix alphaB of pKID interacts with a hydrophobic groove defined by helices alpha1 and alpha3 of KIX. The other pKID helix, alphaA, contacts a different face of the alpha3 helix. The phosphate group of the critical phosphoserine residue of pKID forms a hydrogen bond to the side chain of Tyr-658 of KIX. The structure provides a model for interactions between other transactivation domains and their targets.
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