PMID: 21642970

Authors:

Phan AT, Kuryavyi V, Darnell JC, Serganov A, Majumdar A, Ilin S, Raslin T, Polonskaia A, Chen C, Clain D, Darnell RB, Patel DJ

Title:

Structure-function studies of FMRP RGG peptide recognition of an RNA duplex-quadruplex junction.

Journal:

Nat Struct Mol Biol. 2011 Jun 5;18(7):796-804. doi: 10.1038/nsmb.2064.

Abstract:

We have determined the solution structure of the complex between an arginine-glycine-rich RGG peptide from the human fragile X mental retardation protein (FMRP) and an in vitro-selected guanine-rich (G-rich) sc1 RNA. The bound RNA forms a newly discovered G-quadruplex separated from the flanking duplex stem by a mixed junctional tetrad. The RGG peptide is positioned along the major groove of the RNA duplex, with the G-quadruplex forcing a sharp turn of R(10)GGGGR(15) at the duplex-quadruplex junction. Arg10 and Arg15 form cross-strand specificity-determining intermolecular hydrogen bonds with the major-groove edges of guanines of adjacent Watson-Crick G*C pairs. Filter-binding assays on RNA and peptide mutations identify and validate contributions of peptide-RNA intermolecular contacts and shape complementarity to molecular recognition. These findings on FMRP RGG domain recognition by a combination of G-quadruplex and surrounding RNA sequences have implications for the recognition of other genomic G-rich RNAs.