title: A conserved charged single α-helix with a putative steric role in paraspeckle formation.
abstract: Paraspeckles are subnuclear particles involved in the regulation of mRNA expression. They are formed by the association of DBHS family proteins and the NEAT1 long noncoding RNA. Here, we show that a recently identified structural motif, the charged single α-helix, is largely conserved in the DBHS family. Based on the available structural data and a previously suggested multimerization scheme of DBHS proteins, we built a structural model of a (PSPC1/NONO)(n) multimer that might have relevance in paraspeckle formation. Our model contains an extended coiled-coil region that is followed by and partially overlaps with the predicted charged single α-helix. We suggest that the charged single α-helix can act as an elastic ruler governing the exact positioning of the dimeric core structures relative to each other during paraspeckle assembly along the NEAT1 noncoding RNA.
authors.affiliation: Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1083 Budapest, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Dobson
authors.affiliation: Eötvös Loránd University, Department of Biochemistry, H-1117 Budapest, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Nyitray
authors.affiliation: Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1083 Budapest, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Gáspári
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D004268:DNA-Binding Proteins; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D008969:Molecular Sequence Data; D034521:Nuclear Matrix-Associated Proteins / Q000737:chemistry*; D009687:Nuclear Proteins / Q000737:chemistry*; D050810:Octamer Transcription Factors / Q000737:chemistry*; D000072670:PTB-Associated Splicing Factor; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D016601:RNA-Binding Proteins / Q000737:chemistry*
chemical_list: D004268:DNA-Binding Proteins; C083214:NONO protein, human; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; D050810:Octamer Transcription Factors; C450059:PSPC1 protein, human; D000072670:PTB-Associated Splicing Factor; D016601:RNA-Binding Proteins
keywords: charged single α-helix; coiled coil; multimerization; paraspeckle; structural modeling