Membrane deformation by human pacsin isoforms.

<p>A. Domain organization and structure of pacsin-1. The structure shows a F-BAR domain dimer with the protomers shown in green and orange, respectively. B. SAXS-based comparison of full-length pacsin-1 in solution and in crystals. Distant distribution functions, Rg and Dmax values were determined based on the full-length crystal structure <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0051628#pone.0051628-Rao1" target="_blank">[28]</a> and the solution scattering data <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0051628#pone.0051628-Wang1" target="_blank">[27]</a>. R_g/D_max (crystal) = 212/60 Å; R_g/D_max (SAXS) = 215/58 Å. Discrepancies between the respective distance distribution functions can be explained by the flexible linkers that connect the F-BAR and SH3 domains and were not modeled in the crystal structures. C. Negative-stain electron micrographs. The membrane deformation potential of human pacsin isoforms and their isolated F-BAR domains was monitored by EM. Folch fraction I liposomes were incubated with purified proteins (5–10 µM), and processed as described in Materials and Methods. Arrows indicate specific membrane morphologies (solid arrows, pearling structures; dashed arrows, narrow tubules; open triangles, wide tubules). Inset shows liposome-only control; scale bar, 100 nm.