2LWW: NMR structure of RelA-TAD/CBP-TAZ1 complex

Citation:
Abstract
NF-kappaB plays a vital role in cellular immune and inflammatory response, survival, and proliferation by regulating the transcription of various genes involved in these processes. To activate transcription, RelA (a prominent NF-kappaB family member) interacts with transcriptional co-activators like CREB-binding protein (CBP) and its paralog p300 in addition to its cognate kappaB sites on the promoter/enhancer regions of DNA. The RelA:CBP/p300 complex is comprised of two components--first, DNA binding domain of RelA interacts with the KIX domain of CBP/p300, and second, the transcriptional activation domain (TAD) of RelA binds to the TAZ1 domain of CBP/p300. A phosphorylation event of a well-conserved RelA(Ser276) is prerequisite for the former interaction to occur and is considered a decisive factor for the overall RelA:CBP/p300 interaction. The role of the latter interaction in the transcription of RelA-activated genes remains unclear. Here we provide the solution structure of the latter component of the RelA:CBP complex by NMR spectroscopy. The structure reveals the folding of RelA-TA2 (a section of TAD) upon binding to TAZ1 through its well-conserved hydrophobic sites in a series of grooves on the TAZ1 surface. The structural analysis coupled with the mechanistic studies by mutational and isothermal calorimetric analyses allowed the design of RelA-mutants that selectively abrogated the two distinct components of the RelA:CBP/p300 interaction. Detailed studies of these RelA mutants using cell-based techniques, mathematical modeling, and genome-wide gene expression analysis showed that a major set of the RelA-activated genes, larger than previously believed, is affected by this interaction. We further show how the RelA:CBP/p300 interaction controls the nuclear response of NF-kappaB through the negative feedback loop of NF-kappaB pathway. Additionally, chromatin analyses of RelA target gene promoters showed constitutive recruitment of CBP/p300, thus indicating a possible role of CBP/p300 in recruitment of RelA to its target promoter sites.
PDB ID: 2LWWDownload
MMDB ID: 113299
PDB Deposition Date: 2012/8/7
Updated in MMDB: 2013/09
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Biological Unit for 2LWW: dimeric; determined by author
Molecular Components in 2LWW
Label Count Molecule
Proteins (2 molecules)
1
Creb-binding Protein(Gene symbol: Crebbp)
Molecule annotation
1
Nuclear Transcription Factor Rela
Molecule annotation
Chemicals (3 molecules)
1
3
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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