Identifying and characterising Thrap3, Bclaf1 and Erh direct interactions using cross-linking mass spectrometry

Cross-linking mass spectrometry (XL-MS) is a powerful technology capable of yielding structural insights across the complex cellular protein interaction network. We performed XL-MS using MS-cleavable cross-linker disuccinimidyl sulfoxide (DSSO) on endogenous affinity-purified BAF complex. We identified numerous crosslinks between three BAF co-purifying proteins, namely Thrap3, Bclaf1 and Erh. Our data suggests that Bclaf1, Erh and Thrap3 interact closely and might represent a stable complex. The XL data allowed us to map interaction surfaces on Thrap3 and B, which overlap with the non-disordered portions of both proteins.