Fig. 5: PR-A and PR-B differentially interact with SRC3 and are stabilized by p300 addition.

A. Consolidated differential HDX-MS results for SRC3, comparing the changes induced by PR-A and p300 binding in the presence and absence of PRE DNA. B Consolidated HDX-MS plot of SRC3 exchange, with PR-B comparisons in the same order as PR-A. The motifs highlighted are the following: bHLH (orange), PAS (purple), LXXLL motifs (yellow), CREBBP Interaction Domain (teal), and acetyltransferase domain (dark blue). Each color represents the percent change in deuterium incorporation (Δ%D), following the scale shown, where darker blues correspond to decreased differential deuterium exchange and warmer reds correspond to increases in differential deuterium exchange. Gray overlays indicate no significant changes, and black indicates peptides not detected in the HDX-MS experiment. C Selected deuterium uptake plots for peptides that contain LXXLL motifs 1, 2, and 3. The %D uptake indicates the percent deuterium uptake over time for the PR-A:SRC3 ± DNA and PR-A:SRC3:p300 ± DNA HDX experiments. Data points are the mean of three replicates (N = 3) with error bars corresponding to the standard deviation in the differential deuterium uptake for each time point. Statistics were derived using two-way ANOVA with Tukey post hoc correction for multiple comparisons, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Exchange data is representative of a full seven-timepoint differential HDX experiment with sample injection after 10, 30, 60, 300, 900, and 3600 s of deuterium exchange.