Download MendeleyUtilizing the GAAA Tetraloop/Receptor To Facilitate Crystal Packing and Determination of the Structure of a CUG RNA Helix.
Coonrod, L.A., Lohman, J.R., Berglund, J.A.(2012) Biochemistry 51: 8330-8337
- PubMed: 23025897
- DOI: https://doi.org/10.1021/bi300829w
- Primary Citation of Related Structures:
4FNJ - PubMed Abstract:
Myotonic dystrophy type 1 (DM1) is a microsatellite expansion disorder caused by the aberrant expansion of CTG repeats in the 3'-untranslated region of the DMPK gene. When transcribed, the toxic RNA CUG repeats sequester RNA binding proteins, which leads to disease symptoms. The expanded CUG repeats can adopt a double-stranded structure, and targeting this helix is a therapeutic strategy for DM1. To improve our understanding of the 5'CUG/3'GUC motif and how it may interact with proteins and small molecules, we designed a short CUG helix attached to a GAAA tetraloop/receptor to facilitate crystal packing. Here we report the highest-resolution structure (1.95 Å) to date of a GAAA tetraloop/receptor and the CUG helix it was used to crystallize. Within the CUG helix, we identify two different forms of noncanonical U-U pairs and reconfirm that CUG repeats are essentially A-form. An analysis of all noncanonical U-U pairs in the context of CUG repeats revealed six different classes of conformations that the noncanonical U-U pairs are able to adopt.
Organizational Affiliation:
Institute of Molecular Biology and Department of Chemistry, University of Oregon, Eugene, OR 97403, USA.
