Sortin nexin 17/31 are known as PX-FERM proteins, a sub-group of the PX superfamily that contain a defining PtdInsP-binding PX domain, and a C-terminal 4.1, ezrin, radixin, moesin (FERM) domain [1,2]. They are modular peripheral membrane proteins that act as central scaffolds mediating protein-lipid interactions, cargo binding, and regulatory protein recruitment [3]. The FERM domain omprises three lobes termed F1, F2, and F3: F1 adopts a ubiquitin-like fold, F2 is a helical structure similar to acyl-CoA binding protein, and F3 is similar to the phosphotyrosine binding (PTB)/pleckstrin homology domain and referred to as atypical FERM domain (Pfam:PF18116) [2]. This entry represents the F2 lobe [2].

1: Structural basis for endosomal trafficking of diverse transmembrane cargos by PX-FERM proteins. Ghai R, Bugarcic A, Liu H, Norwood SJ, Skeldal S, Coulson EJ, Li SS, Teasdale RD, Collins BM; Proc Natl Acad Sci U S A. 2013;110:E643-E652. PMID:23382219

2: Structural determinants for binding of sorting nexin 17 (SNX17) to the cytoplasmic adaptor protein Krev interaction trapped 1 (KRIT1). Stiegler AL, Zhang R, Liu W, Boggon TJ; J Biol Chem. 2014;289:25362-25373. PMID:25059659

3: Measuring interactions of FERM domain-containing sorting Nexin proteins with endosomal lipids and cargo molecules. Ghai R, Mobli M, Collins BM; Methods Enzymol. 2014;534:331-349. PMID:24359963