Extended Data Fig. 1. The FOXA α-helix binds core histones.

a, Schematic of crosslinking of histone octamers used as input and FOXA1. SDS-PAGE analysis of FOXA1 or FOXA1 crosslinked to core histones, stained with Coomassie blue. Crosslinked products of a mobility expected for FOXA1 and core histone together are noted as band A and band B. The full blot gel is presented in the Source Data files. b, Underlined sequences are identified by peptide mass matching while the subset highlighted by green are used for relative peptide quantification in Extended Data Figure 2. c, Strategy to map candidate interaction sites, explaining how crosslinked peptides gain a much greater mass and become depleted from the m/z spectrum.