The KIX domain of transcriptional co-activator CREB binding protein (CBP) mediates transcription by recruiting transcription factors such as oncogenes c-Myb and mixed lineage leukemia (MLL) [1-2]. These binding partners are largely disordered and attain secondary structure after binding to KIX domain. The KIX domain can bind transcription factors simultaneously to its two opposite binding sites which communicate allostericaly through hydrophobic core [3]. Many transactivation domains for transcription factors interacting with KIX domain belong to established Nine amino acid Transactivation Domain (9aaTAD) family [4].
Standard triple resonance experiments (HNCACB, HN(CO)CACB, HNCO, HNCA, HN(CO)CA) were measured on double labelled 13C,15N KIX domain in order to assign protein backbone. Subsequently, 15N KIX domain was titrated with c-Myb and MLL ligands to observe structural changes and dynamics using 2D HN-HSQC experiment. Dissociation constant for both ligands is in micromolar range.
This work was supported by Ministry of Education, Youth and Sports within programme INTER - ACTION (project No. LTAUSA18168). This research was financially supported by Ministry of Education, Youths and Sports of the Czech Republic within CEITEC 2020 (LQ1601) project.