4gq2 | pdb_00004gq2
S. pombe Nup120-Nup37 complex
Structural highlights
Function[NU120_SCHPO] Functions as a component of the nuclear pore complex (NPC). NPC components, collectively referred to as nucleoporins (NUPs), can play the role of both NPC structural components and of docking or interaction partners for transiently associated nuclear transport factors. Active directional transport is assured by both, a Phe-Gly (FG) repeat affinity gradient for these transport factors across the NPC and a transport cofactor concentration gradient across the nuclear envelope.[1] Publication Abstract from PubMedThe coatomer module of the nuclear pore complex borders the cylinder-like nuclear pore-membrane domain of the nuclear envelope. In evolution, a single coatomer module increases in size from hetero-heptamer (Saccharomyces cerevisiae) to hetero-octamer (Schizosaccharomyces pombe) to hetero-nonamer (Metazoa). Notably, the heptamer-octamer transition proceeds through the acquisition of the nucleoporin Nup37. How Nup37 contacts the heptamer remained unknown. Using recombinant nucleoporins, we show that Sp-Nup37 specifically binds the Sp-Nup120 member of the hetero-heptamer but does not bind an Sc-Nup120 homolog. To elucidate the Nup37-Nup120 interaction at the atomic level, we carried out crystallographic analyses of Sp-Nup37 alone and in a complex with an N-terminal, approximately 110-kDa fragment of Sp-Nup120 comprising residues 1-950. Corroborating structural predictions, we determined that Nup37 folds into a seven-bladed beta-propeller. Several disordered surface regions of the Nup37 beta-propeller assume structure when bound to Sp-Nup120. The N-terminal domain of Sp-Nup120(1-950) also folds into a seven-bladed propeller with a markedly protruding 6D-7A insert and is followed by a contorted helical domain. Conspicuously, this 6D-7A insert contains an extension of 50 residues which also is highly conserved in Metazoa but is absent in Sc-Nup120. Strikingly, numerous contacts with the Nup37 beta-propeller are located on this extension of the 6D-7A insert. Another contact region is situated toward the end of the helical region of Sp-Nup120(1-950). Our findings provide information about the evolution and the assembly of the coatomer module of the nuclear pore complex. Structural evolution of the membrane-coating module of the nuclear pore complex.,Liu X, Mitchell JM, Wozniak RW, Blobel G, Fan J Proc Natl Acad Sci U S A. 2012 Oct 9;109(41):16498-503. doi:, 10.1073/pnas.1214557109. Epub 2012 Sep 26. PMID:23019579[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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