5h1x

Publication Abstract from PubMed

The central transport channel of the vertebrate nuclear pore complex (NPC) consists of nucleoporins: Nup62, Nup54, and Nup58. The coiled-coil domains in alpha-helical regions of these nucleoporins are thought to be crucial for several protein-protein interactions in the NPC subcomplexes. In this study, we determined the crystal structure of the coiled-coil domain of rat Nup62 fragment (residues 362-425) to 2.4 A resolution. The crystal structure shows the conserved coiled-coil domain as a parallel three-helix bundle for the Nup62(362-425) fragment. On the basis of our size exclusion chromatography coupled to multiangle light scattering analysis and glutaraldehyde cross-linking experiments, we conclude that the Nup62(362-425) fragment displays dynamic behavior in solution and can also exist in either homodimeric or homotrimeric states. Our comparative analysis of the rat Nup62(362-425) homotrimeric structure with previously reported heterotrimeric structures [rat Nup62(362-425).Nup54(346-407) and Xenopus Nup62(358-485).Nup54(315-450).Nup58(283-406) complexes] demonstrates the structural basis for parallel triple-helix bundle formation for Nup62 with different partners. Moreover, we show that the coiled-coil domain of Nup62 is sufficient for interaction with the coiled-coil domain of rat Exo70, a protein in an exocyst complex. On the basis of these observations, we suggest the plausible chain replacement mechanism that yields to diverse protein assemblies with Nup62. In summary, the coiled-coil motif present in Nup62 imparts the ability to form a homotrimer and heterotrimers either with Nup54 or with Nup54-Nup58 within the NPCs as well as with Exo70 beyond the NPCs. These complexes of Nup62 suggest the crucial role of the coiled-coil motifs in providing plasticity to various modular assemblies.

The Nup62 Coiled-Coil Motif Provides Plasticity for Triple-Helix Bundle Formation.,Dewangan PS, Sonawane PJ, Chouksey AR, Chauhan R Biochemistry. 2017 Jun 6;56(22):2803-2811. doi: 10.1021/acs.biochem.6b01050. Epub, 2017 Apr 26. PMID:28406021^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.