Loop lengths of G-quadruplex structures affect the G-quadruplex DNA binding selectivity of the RGG motif in Ewing's sarcoma

Biochemistry. 2011 Jun 14;50(23):5369-78. doi: 10.1021/bi2003857. Epub 2011 May 18.

Abstract

The G-quadruplex nucleic acid structural motif is a target for designing molecules with potential anticancer properties. To achieve therapeutic selectivity by targeting the G-quadruplex, the molecules must be able to differentiate between the DNA of different G-quadruplexes. We recently reported that the Arg-Gly-Gly repeat (RGG) of the C-terminus in Ewing's sarcoma protein (EWS), which is a group of dominant oncogenes that arise due to chromosomal translocations, is capable of binding to G-quadruplex telomere DNA and RNA via arginine residues and stabilize the G-quadruplex DNA form in vitro. Here, we show that the RGG of EWS binds preferentially to G-quadruplexes with longer loops, which is not related to the topology of the G-quadruplex structure. Moreover, the G-quadruplex DNA binding of the RGG in EWS depends on the phosphate backbone of the loops in the G-quadruplex DNA. We also investigated the G-quadruplex DNA binding activity of the N- and C-terminally truncated RGG to assess the role of the regions in the RGG in G-quadruplex DNA binding. Our findings indicate that the RGG and the other arginine-rich motif of residues 617-656 of the RGG in EWS are important for the specific binding to G-quadruplex DNA. These findings will contribute to the development of molecules that selectively target different G-quadruplex DNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Arginine / genetics
  • DNA / chemistry*
  • DNA / metabolism
  • G-Quadruplexes*
  • Glutathione Transferase / chemistry
  • Glutathione Transferase / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Structure, Tertiary / genetics
  • RNA-Binding Protein EWS / chemistry*
  • RNA-Binding Protein EWS / genetics
  • RNA-Binding Protein EWS / metabolism

Substances

  • RNA-Binding Protein EWS
  • DNA
  • Arginine
  • Glutathione Transferase