Nup188 is one of the many peptides that make up the nucleoporin complex (NPC), and is found across eukaryotes [1,2]. The Nup188 subcomplex (Nic96p-Nup188p-Nup192p-Pom152p) is one of at least six that make up the NPC, and as such is symmetrically localised on both faces of the NPC at the nuclear end, being integrally bound to the C terminus of Pom34p [3]. This protein folds into an extended stack of helices where the N-terminal forms a closed ring (subdivided into subdomains I-III in [2]) and the C-terminal forms a more regular, superhelical structure [2]. This entry represents a beta-stranded SH3-like domain inserted in subdomain III from Nup188 N-terminal region, which is a circular permutation from canonical SH3 domain [2].

1: Identification of a new vertebrate nucleoporin, Nup188, with the use of a novel organelle trap assay. Miller BR, Powers M, Park M, Fischer W, Forbes DJ; Mol Biol Cell. 2000;11:3381-3396. PMID:11029043

2: Scaffold nucleoporins Nup188 and Nup192 share structural and functional properties with nuclear transport receptors. Andersen KR, Onischenko E, Tang JH, Kumar P, Chen JZ, Ulrich A, Liphardt JT, Weis K, Schwartz TU; Elife. 2013;2:e00745. PMID:23795296

3: The integral membrane protein Pom34p functionally links nucleoporin subcomplexes. Miao M, Ryan KJ, Wente SR; Genetics. 2006;172:1441-1457. PMID:16361228