Download MendeleyAllosteric communication in the KIX domain proceeds through dynamic repacking of the hydrophobic core.
Bruschweiler, S., Konrat, R., Tollinger, M.(2013) ACS Chem Biol 8: 1600-1610
- PubMed: 23651431
- DOI: https://doi.org/10.1021/cb4002188
- Primary Citation of Related Structures:
2LXS, 2LXT - PubMed Abstract:
The KIX domain of the transcriptional coactivator CREB binding protein (CBP) co-operatively mediates interactions between transcription factors. Binding of the transcription factor mixed-lineage leukemia (MLL) induces the formation of a low-populated conformer of KIX that resembles the conformation of the KIX domain in the presence of a second transcription factor molecule. NMR spin relaxation studies have previously shown that allosteric coupling proceeds through a network of hydrophobic core residues that bridge the two binding sites. Here we describe high-resolution NMR solution structures of the binary complex of KIX with MLL and the ternary complex of KIX formed with MLL and phosphorylated kinase inducible domain of CREB (pKID) as a second ligand. We show that binding of pKID to the binary complex of KIX with MLL is accompanied by a defined repacking of the allosteric network in the hydrophobic core of the protein. Rotamer populations derived from methyl group (13)C chemical shifts reveal a dynamic contribution to the repacking process that is not captured by the structural coordinates and exemplify the dynamic nature of allosteric communication in the KIX domain.
Organizational Affiliation:
Institute of Organic Chemistry, Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck , Innrain 80/82, A-6020 Innsbruck, Austria.
