Extended Data Fig. 3: Dynamic architecture of dimeric Sgt2 with independent domains.
From: Remote on–off switching of protein activity by intrinsically disordered region
a, Superpositions of 1H-15N HSQC spectra and 1H-13C methyl-TROSY spectra of individual domains (or combinations) compared with those of full-length Sgt2 or domain combinations. The color scheme represents different domains as labeled. For clarity, the spectra on top are shown with outer contours only. Most residues with perturbations are located at domain interfaces (for example, labeled in the first three overlays in the top row). The similarity of signals from all three domains to their isolated counterparts suggests a highly dynamic architecture, with each domain behaving as an independent structural entity. The lower right plot in panel (a) compares the 1H-15N HSQC signal intensities of Sgt2C (I) with those in Sgt2FL (I0), plotted against residue numbers. Only well-separated peaks were analyzed. Most residues exhibit less than a 50% increase in intensity despite a 5.7-fold decrease in molecular weight, further suggesting the dynamic independence of Sgt2C. b, SAXS analysis of Sgt2NT, displaying the experimental SAXS curve along with the pair-probability, P(r), functions. The presence of multiple peaks in the P(r) function suggests the presence of multiple folded domains. c, SAXS analysis of Sgt2FL, showing the experimental SAXS curve and corresponding P(r) functions. This figure underscores the dynamic nature of dimeric Sgt2, wherein its three individual domains exhibit independent behavior. d, NMR-derived order parameter (S2) profiles of selected methyl residues in full-length Sgt2, highlighting fast (ps-ns) dynamics. e, Comparison of 15N R2 relaxation rates for isolated Sgt2C (green) and Sgt2C within full-length Sgt2 (orange), with error bars representing standard deviations from data fitting, and centre indicating fitted R₂ values. Only well-separated peaks were analyzed. The results indicate that Sgt2C remains highly dynamic and does not form strong interdomain interactions within full-length Sgt2.
