4ga0
From Proteopedia
Structure of the N-terminal domain of Nup358
Structural highlights
Disease[RBP2_HUMAN] Defects in RANBP2 are the cause of encephalopathy acute infection-induced type 3 (IIAE3) [MIM:608033]. A rapidly progressive encephalopathy manifesting in susceptibile individuals with seizures and coma. It can occur within days in otherwise healthy children after common viral infections such as influenza and parainfluenza, without evidence of viral infection of the brain or inflammatory cell infiltration. Brain T2-weighted magnetic resonance imaging reveals characteristic symmetric lesions present in the thalami, pons and brainstem. Note=Mutations in the RANBP2 gene predispose to IIAE3, but by themselves are insufficient to make the phenotype fully penetrant; additional genetic and environmental factors are required (PubMed:19118815).[1] Function[RBP2_HUMAN] E3 SUMO-protein ligase which facilitates SUMO1 and SUMO2 conjugation by UBE2I. Involved in transport factor (Ran-GTP, karyopherin)-mediated protein import via the F-G repeat-containing domain which acts as a docking site for substrates. Could also have isomerase or chaperone activity and may bind RNA or DNA. Component of the nuclear export pathway. Specific docking site for the nuclear export factor exportin-1.[2] [3] [4] [5] Publication Abstract from PubMedKey steps in mRNA export are the nuclear assembly of messenger ribonucleoprotein particles (mRNPs), the translocation of mRNPs through the nuclear pore complex (NPC), and the mRNP remodeling events at the cytoplasmic side of the NPC. Nup358/RanBP2 is a constituent of the cytoplasmic filaments of the NPC specific to higher eukaryotes and provides a multitude of binding sites for the nucleocytoplasmic transport machinery. Here, we present the crystal structure of the Nup358 N-terminal domain (NTD) at 0.95A resolution. The structure reveals an alpha-helical domain that harbors three central tetratricopeptide repeats (TPRs), flanked on each side by an additional solvating amphipathic alpha helix. Overall, the NTD adopts an unusual extended conformation that lacks the characteristic peptide-binding groove observed in canonical TPR domains. Strikingly, the vast majority of the NTD surface exhibits an evolutionarily conserved, positive electrostatic potential, and we demonstrate that the NTD possesses the capability to bind single-stranded RNA in solution. Together, these data suggest that the NTD contributes to mRNP remodeling events at the cytoplasmic face of the NPC. Crystal Structure of the N-Terminal Domain of Nup358/RanBP2.,Kassube SA, Stuwe T, Lin DH, Antonuk CD, Napetschnig J, Blobel G, Hoelz A J Mol Biol. 2012 Sep 7. pii: S0022-2836(12)00719-X. doi:, 10.1016/j.jmb.2012.08.026. PMID:22959972[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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