This dataset is related to "MLL1 minimal catalytic complex is a dynamic conformational ensemble susceptible to pharmacological allosteric disruption" (Lilia Kaustov, Alexander Lemak, Hong Wu, Marco Faini, Lixin Fan, Xianyang Fang, Hong Zeng, Shili Duan, Abdellah Allali-Hassani, Yong Wei, Masoud Vedadi, Ruedi Aebersold, Yunxing Wang, Scott Houliston, Cheryl H. Arrowsmith) . The repository contains the data used in the modeling of WDR5-RbBP5-MLL1 trimeric complex, the optimal ensemble of models, and the representative models for major and minor populations. The modeling is performed based on saxs and cross-link MS data, crystallographic structures, and comparative models using coarse-grained MD simulations and Sparse Ensemble Selection method (SES) for optimal ensemble selection.