6SVS

Crystal Structure of U:A-U-rich RNA triple helix with 11 consecutive base triples

Summary for 6SVS

• Entry DOI: 10.2210/pdb6svs/pdb
• Descriptor: RNA (79-mer), GLYCEROL, CALCIUM ION, ... (6 entities in total)
• Functional Keywords: rna triple helix poly(u:a-u) base triple, rna
• Biological source: Homo sapiens
• Total number of polymer chains: 2
• Total formula weight: 51576.51

Authors

Ruszkowska, A.,Ruszkowski, M.,Hulewicz, J.P.,Dauter, Z.,Brown, J.A. (deposition date: 2019-09-18, release date: 2020-01-01, Last modification date: 2024-01-24)

Primary citation

Ruszkowska, A.,Ruszkowski, M.,Hulewicz, J.P.,Dauter, Z.,Brown, J.A.
Molecular structure of a U•A-U-rich RNA triple helix with 11 consecutive base triples.
Nucleic Acids Res., 48:3304-3314, 2020

PubMed Abstract: Three-dimensional structures have been solved for several naturally occurring RNA triple helices, although all are limited to six or fewer consecutive base triples, hindering accurate estimation of global and local structural parameters. We present an X-ray crystal structure of a right-handed, U•A-U-rich RNA triple helix with 11 continuous base triples. Due to helical unwinding, the RNA triple helix spans an average of 12 base triples per turn. The double helix portion of the RNA triple helix is more similar to both the helical and base step structural parameters of A'-RNA rather than A-RNA. Its most striking features are its wide and deep major groove, a smaller inclination angle and all three strands favoring a C3'-endo sugar pucker. Despite the presence of a third strand, the diameter of an RNA triple helix remains nearly identical to those of DNA and RNA double helices. Contrary to our previous modeling predictions, this structure demonstrates that an RNA triple helix is not limited in length to six consecutive base triples and that longer RNA triple helices may exist in nature. Our structure provides a starting point to establish structural parameters of the so-called 'ideal' RNA triple helix, analogous to A-RNA and B-DNA double helices.

PubMed: 31930330
DOI: 10.1093/nar/gkz1222

Experimental method

X-RAY DIFFRACTION (2.5 Å)