Twenty Crystal Structures of Bromodomain and PHD Finger Containing Protein 1 (BRPF1)/Ligand Complexes Reveal Conserved Binding Motifs and Rare Interactions.

BRPF1 plays a scaffolding role in transcription. We report on fragment screening by high-throughput docking to the BRPF1 bromodomain which resulted in six chemotypes with very favorable ligand efficiency (0.45-0.50 kcal/mol per non-hydrogen atom). Twenty crystal structures of BRPF1/ligand complexes show structural conservation in the acetyllysine binding site, common binding motifs, and unusual interactions (e.g., the replacement of a conserved water molecule). The structural information is useful for the design of chemical probes.