• Media type: E-Article
  • Title: Crystal structure reveals specific recognition of a G-quadruplex RNA by a β-turn in the RGG motif of FMRP
  • Contributor: Vasilyev, Nikita; Polonskaia, Anna; Darnell, Jennifer C.; Darnell, Robert B.; Patel, Dinshaw J.; Serganov, Alexander
  • Published: National Academy of Sciences, 2015
  • Published in: Proceedings of the National Academy of Sciences of the United States of America, 112 (2015) 39, Seite E5391-E5400
  • Language: English
  • ISSN: 0027-8424; 1091-6490
  • Origination:
  • Footnote:
  • Description: Fragile X Mental Retardation Protein (FMRP) is a regulatory RNA binding protein that plays a central role in the development of several human disorders including Fragile X Syndrome (FXS) and autism. FMRP uses an arginine-glycine-rich (RGG) motif for specific interactions with guanine (G)-quadruplexes, mRNA elements implicated in the disease-associated regulation of specific mRNAs. Here we report the 2.8-Å crystal structure of the complex between the human FMRP RGG peptide bound to the in vitro selected G-rich RNA. In this model system, the RNA adopts an intramolecular K⁺-stabilized G-quadruplex structure composed of three G-quartets and a mixed tetrad connected to an RNA duplex. The RGG peptide specifically binds to the duplex–quadruplex junction, the mixed tetrad, and the duplex region of the RNA through shape complementarity, cation–π interactions, and multiple hydrogen bonds. Many of these interactions critically depend on a type I β-turn, a secondary structure elementwhose formationwas not previously recognized in the RGG motif of FMRP. RNA mutagenesis and footprinting experiments indicate that interactions of the peptide with the duplex–quadruplex junction and the duplex of RNA are equally important for affinity and specificity of the RGG–RNA complex formation. These results suggest that specific binding of cellular RNAs by FMRP may involve hydrogen bonding with RNA duplexes and that RNA duplex recognition can be a characteristic RNA binding feature for RGG motifs in other proteins.
  • Access State: Open Access