The Bin/Amphiphysin/Rvs (BAR) domain of uncharacterized Sorting Nexins
BAR domains are dimerization, lipid binding and curvature sensing modules found in many different proteins with diverse functions. This subfamily is composed of uncharacterized proteins with similarity to sorting nexins (SNXs), which are Phox homology (PX) domain containing proteins that are involved in regulating membrane traffic and protein sorting in the endosomal system. SNXs differ from each other in their lipid-binding specificity, subcellular localization and specific function in the endocytic pathway. A subset of SNXs also contain BAR domains. The PX-BAR structural unit determines the specific membrane targeting of SNXs. BAR domains form dimers that bind to membranes, induce membrane bending and curvature, and may also be involved in protein-protein interactions.