Structural Characteristics of BAR Domain Superfamily to Sculpt the Membrane

Membrane dynamics is an essential process for cell locomotion, cytokinesis, vesicular transport and organelle morphogenesis. Formation of tubes or buds from a nearly flat membrane is a widely spread feature of the membrane shape changes. The BAR (Bin/Amphiphysin/Rvs-homology) domain dimers exhibit long extended curved shapes and appear to be outstandingly suitable modules for this purpose. So far, crystal structures of 18 independent BAR domains including inverse-BAR domains and FCH-BAR domains have been reported. These atomic models show a vast variation of dimer shapes on a common and simple basic framework. Comparison of the structural variations with respect to differences in membrane sculpting properties provide useful clues about the mechanisms for modifying the framework into a particular dimer that generates and/or senses a distinct curvature set of the membrane.