Article

  • The EMBO Journal (2006) 25, 5126 - 5137
  • doi:10.1038/sj.emboj.7601385

Published online: 12 October 2006

Molecular basis of RNA recognition and TAP binding by the SR proteins SRp20 and 9G8

Yann Hargous1,a, Guillaume M Hautbergue2,a, Aura M Tintaru2,3,a, Lenka Skrisovska1, Alexander P Golovanov3, James Stevenin4,5,6,7, Lu-Yun Lian3,b, Stuart A Wilson2 and Frédéric H-T Allain1

  1. Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
  2. Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
  3. Faculty of Life Science, University of Manchester, Manchester, UK
  4. IGBMC, Department of Transcription, Illkirch, France
  5. Inserm U596, Illkirch, France
  6. CNRS UMR7104, Illkirch, France
  7. University of Strasbourg, Strasbourg, France

Correspondence to:

Frédéric H-T Allain, Institute of Molecular Biology and Biophysics, ETH Zurich, Swiss Federal Institute of Technology (ETH) Zurich, 8093 Zurich, Switzerland. Tel.: +41 1 633 39 40; Fax: +41 1 633 12 94; E-mail: allain@mol.biol.ethz.ch

Stuart A Wilson, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Sheffield S10 2TN, UK. Tel.: +44 114 222 2849; Fax: +44 114 222 2800; E-mail: stuart.wilson@sheffield.ac.uk

aThese authors contributed equally to this work

bPresent address: School of Biological Sciences, Biosciences Building, University of Liverpool, Liverpool L69 7ZB, UK

Received 30 May 2006; Accepted 18 September 2006


The sequence-specific RNA-binding proteins SRp20 and 9G8 are the smallest members of the serine- and arginine-rich (SR) protein family, well known for their role in splicing. They also play a role in mRNA export, in particular of histone mRNAs. We present the solution structures of the free 9G8 and SRp20 RNA recognition motifs (RRMs) and of SRp20 RRM in complex with the RNA sequence 5'CAUC3'. The SRp20-RNA structure reveals that although all 4 nt are contacted by the RRM, only the 5' cytosine is primarily recognized in a specific way. This might explain the numerous consensus sequences found by SELEX (systematic evolution of ligands by exponential enrichment) for the RRM of 9G8 and SRp20. Furthermore, we identify a short arginine-rich peptide adjacent to the SRp20 and 9G8 RRMs, which does not contact RNA but is necessary and sufficient for interaction with the export factor Tip-associated protein (TAP). Together, these results provide a molecular description for mRNA and TAP recognition by SRp20 and 9G8.

  • Keywords:

    • mRNA export,
    • NMR,
    • RRM,
    • SR protein,
    • TAP