Figure 5: IM30 rings bind perpendicularly to membrane surfaces.
From: IM30 triggers membrane fusion in cyanobacteria and chloroplasts
(a) Cryo-TEM image showing IM30 as extra electron density attached to a liposome. Scale bar, 20 nm. (b) Superposition of the extra density with the side-view of a 3D reconstructed IM30 ring being depicted in projection view (approximately 30 nm in diameter). (c) Experimental (circles) and calculated (line) SFG-spectra of IM30 bound to a model MGDG/PG monolayer at the air–water interface using the ssp polarization combination. The experiment was repeated two times. The calculated spectra match the experimental data well for upright monomer orientations. A tilt angle of 0° with respect to the surface normal was used for the calculation shown. (d) Magnification of the box in b, depicting the 3D reconstruction in an isosurface view. Note that the 3D reconstruction matches the extra electron density in size and shape, indicating perpendicular binding of IM30 to the membrane surface.
