Compound 9 shows weak affinity to both TRIM24 and TRIM33 when any of the peptides were used, consistent with the idea that this compound does not bind to exclusively the BRD or PHD of these proteins. To identify possible binding locations for compounds 9-11, beyond the BRD and KAc, the CCDC SuperStar package was used to detect cavities in TRIM33β. This approach identified the KAc binding site, a shallow site at the K4Me 0 binding region, and a larger cavity between the BRD and PHD (Figure ). The analysis also showed there was a cavity at the base of the construct. Based on these results, it is possible that compound 9 binds in this interdomain cleft, explaining the AlphaScreen assay results.