Skip to main content
. Author manuscript; available in PMC: 2012 Aug 1.
Published in final edited form as: Biopolymers. 2011 Apr 20;95(8):559–571. doi: 10.1002/bip.21638

FIGURE 6.

FIGURE 6

Metabolite induced structural changes monitored by SAXS. A) SAXS data for the 42 kDa abscisic acid binding domain PYR1 bound (black) and apo (red). B) Porod-Debye plot demonstrating discrete plateaus in bound and apo states suggesting each state can be characterized by discretely folded particles with sharp scattering contrasts. X-ray crystal structure (PDB: 3K3K) characterizes the apo state where it is expected the loop regions reorganize collapsing the structure in the bound state. C) SAXS data for the SAM-1 riboswitch bound (black) and apo (red). Crystal structure of the bound form (blue) changes in the apo state. D) Porod-Debye plot illustrating loss of the Porod plateau in the unbound state suggesting enhanced flexibility of the riboswitch. Transforming apo SAXS data by q3 I(q) vs. q3 (inset) verifies the intensity decay is no longer q−4 but q−3. Data adapted from Nishimura, N.; Hitomi, K.; Arvai, A. S.; Rambo, R. P.; Hitomi, C.; Cutler, S. R.; Schroeder, J. I.; Getzoff, E. D. Science 2009, 326, 1373–1379.