Sorting nexins are a large group of proteins that are localized in the cytoplasm and have the potential for membrane association either through their lipid-binding PX domain (a phospholipid-binding motif) or through protein-protein interactions with membrane-associated protein complexes Some members of this family have been shown to facilitate protein sorting.
Sorting nexins either consist solely of a PX domain (e.g. SNX3) or have a modular structure made up of the PX and additional domains.
A subgroup of sorting nexins (comprising, in humans, SNX1, SNX2, SNX4, SNX5, SNX6, SNX7, SNX8, SNX9, SNX18, SNX30, SNX32 and SNX33) possess a BAR domain at their C-terminus. (The BAR domain of SNXs 1, 2, 4, 7, 8 and 30 is classified by pfam as 'Vps5 C terminal like'.)
An example of a sorting nexin domain structure can be seen here for SNX1:
^Bravo J, Karathanassis D, Pacold CM, et al. (October 2001). "The crystal structure of the PX domain from p40(phox) bound to phosphatidylinositol 3-phosphate". Mol. Cell8 (4): 829–39. doi:10.1016/S1097-2765(01)00372-0. PMID11684018.
^Dixon JE, Worby CA (2002). "Sorting out the cellular functions of sorting nexins". Nat. Rev. Mol. Cell Biol.3 (12): 919–931. doi:10.1038/nrm974. PMID12461558.
^Worby CA, Dixon JE (2002). "Sorting out the cellular functions of sorting nexins". Nat. Rev. Mol. Cell Biol.3 (12): 919–31. doi:10.1038/nrm974. PMID12461558.