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.
Department of Molecular Biology and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Munehito
M
Arai
H Jane
HJ
Dyson
Peter E
PE
Wright
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