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Structural insights into the stabilization of MALAT1 noncoding RNA by a bipartite triple helix
Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a highly-abundant nuclear long noncoding RNA that promotes malignancy. A 3′-stem-loop structure is predicted to confer stability by engaging a downstream A-rich tract in a triple helix, similar to the expression and nuclear retention...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
2014
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4096706/ https://www.ncbi.nlm.nih.gov/pubmed/24952594 http://dx.doi.org/10.1038/nsmb.2844 |
Sumario: | Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a highly-abundant nuclear long noncoding RNA that promotes malignancy. A 3′-stem-loop structure is predicted to confer stability by engaging a downstream A-rich tract in a triple helix, similar to the expression and nuclear retention element (ENE) from the KSHV polyadenylated nuclear RNA. The 3.1-Å resolution crystal structure of the human MALAT1 ENE and A-rich tract reveals a bipartite triple helix containing stacks of five and four U•A-U triples separated by a C(+)•G-C triplet and C-G doublet, extended by two A-minor interactions. In vivo decay assays indicate that this blunt-ended triple helix, with the 3′ nucleotide in a U•A-U triple, inhibits rapid nuclear RNA decay. Interruption of the triple helix by the C-G doublet induces a “helical reset” that explains why triple-helical stacks longer than six do not occur in nature. |
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