Leu628 of the KIX domain of CBP is a key residue for the interaction with the MLL transactivation domain.
Physical interaction between the transactivation domain (TAD) of the mixed-lineage leukemia protein (MLL) and the KIX domain of the cyclic-AMP response element binding protein (CREB) binding protein (CBP) is necessary for MLL-mediated transcriptional activation. We show by alanine-scanning mutagenesis that hydrophobic surface residues of KIX, especially L628, are energetically important for binding the MLL TAD. NMR studies of the KIX-L628A mutant suggest that L628 plays a crucial role in conformational transitions at the MLL binding site, necessary for high affinity interactions with MLL. Unexpectedly, MLL also binds to the c-Myb/phosphorylated kinase-inducible domain of CREB (pKID) site of KIX, highlighting the complex nature of interactions involving intrinsically disordered transcriptional activators.
Arai
Munehito
M
Department of Molecular Biology and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Dyson
H Jane
HJ
Wright
Peter E
PE
D000818:Animals; D001665:Binding Sites; D050882:CREB-Binding Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007930:Leucine; D051379:Mice; D008958:Models, Molecular; D016296:Mutagenesis; D009154:Mutation; D051788:Myeloid-Lymphoid Leukemia Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D015533:Transcriptional Activation
D051788:Myeloid-Lymphoid Leukemia Protein; D050882:CREB-Binding Protein; D007930:Leucine