4MHC

Crystal Structure of a Nucleoporin

Summary for 4MHC

• Entry DOI: 10.2210/pdb4mhc/pdb
• Descriptor: Nucleoporin NUP157 (2 entities in total)
• Functional Keywords: nuclear pore complex, adaptor nucleoporin, dna binding protein, rna binding protein, nucleocytoplasmic transport, beta-propeller, alpha-helical solenoid domain, mrna transport, nucleus, structural protein, gene gating, chromatin organization
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Cellular location: Nucleus, nuclear pore complex: P40064
• Total number of polymer chains: 1
• Total formula weight: 91567.84

Authors

Seo, H.S.,Blus, B.J.,Blobel, G. (deposition date: 2013-08-29, release date: 2013-09-25, Last modification date: 2024-02-28)

Primary citation

Seo, H.S.,Blus, B.J.,Jankovic, N.Z.,Blobel, G.
Structure and nucleic acid binding activity of the nucleoporin Nup157.
Proc.Natl.Acad.Sci.USA, 110:16450-16455, 2013

PubMed Abstract: At the center of the nuclear pore complex (NPC) is a uniquely versatile central transport channel. Structural analyses of distinct segments ("protomers") of the three "channel" nucleoporins yielded a model for how this channel is constructed. Its principal feature is a midplane ring that can undergo regulated diameter changes of as much as an estimated 30 nm. To better understand how a family of "adaptor" nucleoporins--concentrically surrounding this channel--might cushion these huge structural changes, we determined the crystal structure of one adaptor nucleoporin, Nup157. Here, we show that a recombinant Saccharomyces cerevisiae Nup157 protomer, representing two-thirds of Nup157 (residues 70-893), folds into a seven-bladed β-propeller followed by an α-helical domain, which together form a C-shaped architecture. Notably, the structure contains a large patch of positively charged residues, most of which are evolutionarily conserved. Consistent with this surface feature, we found that Nup157(70-893) binds to nucleic acids, although in a sequence-independent manner. Nevertheless, this interaction supports a previously reported role of Nup157, and its paralogue Nup170, in chromatin organization. Based on its nucleic acid binding capacity, we propose a dual location and function of Nup157. Finally, modeling the remaining C-terminal portion of Nup157 shows that it projects as a superhelical stack from the compact C-shaped portion of the molecule. The predicted four hinge regions indicate an intrinsic flexibility of Nup157, which could contribute to structural plasticity within the NPC.

PubMed: 24062435
DOI: 10.1073/pnas.1316607110

Experimental method

X-RAY DIFFRACTION (2.4 Å)