Fig. 2.
EM images of hGBP1. Representative images of hGBP1F in the presence of GTP or GDP·AlFx. Experimental mixture contained 10 μM of hGBP1F and 1 mM of GTP or 200 μM GDP, 300 μM AlCl3, and 10 mM NaF for samples with GDP·AlFx. Reactions were stopped after ∼10 min of incubation with GTP and after ∼20 min incubation with GDP·AlFx (Methods). Ordered polymer structures of hGBP1F in the presence of GTP or GDP·AlFx were identified during at least three independent measurements. Examples of observed ring-like structures are indicated with orange arrows, rods with white arrows, and elongated structures with white arrowheads. Scale bars are as indicated. The geometries of all identified polymer structures are quantified in Fig. S4B.