Structure of a Bacterial Dynamin-like Protein Lipid Tube Provides a Mechanism For Assembly and Membrane Curving

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.cell.2009.11.003 Byline: Harry H. Low (1), Carsten Sachse (1), Linda A. Amos (1), Jan Lowe (1) Keywords: CELLBIO Abstract: Proteins of the dynamin superfamily mediate membrane fission, fusion, and restructuring events by polymerizing upon lipid bilayers and forcing regions of high curvature. In this work, we show the electron cryomicroscopy reconstruction of a bacterial dynamin-like protein (BDLP) helical filament decorating a lipid tube at [approximately equal to]11 A resolution. We fitted the BDLP crystal structure and produced a molecular model for the entire filament. The BDLP GTPase domain dimerizes and forms the tube surface, the GTPase effector domain (GED) mediates self-assembly, and the paddle region contacts the lipids and promotes curvature. Association of BDLP with GMPPNP and lipid induces radical, large-scale conformational changes affecting polymerization. Nucleotide hydrolysis seems therefore to be coupled to polymer disassembly and dissociation from lipid, rather than membrane restructuring. Observed structural similarities with rat dynamin 1 suggest that our results have broad implication for other dynamin family members. Author Affiliation: (1) MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK Article History: Received 24 April 2009; Revised 17 August 2009; Accepted 2 November 2009 Article Note: (miscellaneous) Published: December 24, 2009