Download MendeleyStructural and functional implications of the QUA2 domain on RNA recognition by GLD-1.
Daubner, G.M., Brummer, A., Tocchini, C., Gerhardy, S., Ciosk, R., Zavolan, M., Allain, F.H.(2014) Nucleic Acids Res 42: 8092-8105
- PubMed: 24838563
- DOI: https://doi.org/10.1093/nar/gku445
- Primary Citation of Related Structures:
2MJH - PubMed Abstract:
The STAR family comprises ribonucleic acid (RNA)-binding proteins that play key roles in RNA-regulatory processes. RNA recognition is achieved by a KH domain with an additional α-helix (QUA2) that seems to extend the RNA-binding surface to six nucleotides for SF1 (Homo sapiens) and seven nucleotides for GLD-1 (Caenorhabditis elegans). To understand the structural basis of this probable difference in specificity, we determined the solution structure of GLD-1 KH-QUA2 with the complete consensus sequence identified in the tra-2 gene. Compared to SF1, the GLD-1 KH-QUA2 interface adopts a different conformation resulting indeed in an additional sequence-specific binding pocket for a uracil at the 5'end. The functional relevance of this binding pocket is emphasized by our bioinformatics analysis showing that GLD-1 binding sites with this 5'end uracil are more predictive for the functional response of the messenger RNAs to gld-1 knockout. We further reveal the importance of the KH-QUA2 interface in vitro and that its alteration in vivo affects the level of translational repression dependent on the sequence of the GLD-1 binding motif. In conclusion, we demonstrate that the QUA2 domain distinguishes GLD-1 from other members of the STAR family and contributes more generally to the modulation of RNA-binding affinity and specificity of KH domain containing proteins.
Organizational Affiliation:
Institute of Molecular Biology and Biophysics, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland.
