A novel form of RNA double helix based on G·U and C·A+ wobble base pairing.
RNA
; 24(2): 209-218, 2018 02.
Article
em En
| MEDLINE
| ID: mdl-29122970
ABSTRACT
Wobble base pairs are critical in various physiological functions and have been linked to local structural perturbations in double-helical structures of nucleic acids. We report a 1.38-Å resolution crystal structure of an antiparallel octadecamer RNA double helix in overall A conformation, which includes a unique, central stretch of six consecutive wobble base pairs (W helix) with two G·U and four rare C·A+ wobble pairs. Four adenines within the W helix are N1-protonated and wobble-base-paired with the opposing cytosine through two regular hydrogen bonds. Combined with the two G·U pairs, the C·A+ base pairs facilitate formation of a half turn of W-helical RNA flanked by six regular Watson-Crick base pairs in standard A conformation on either side. RNA melting experiments monitored by differential scanning calorimetry, UV and circular dichroism spectroscopy demonstrate that the RNA octadecamer undergoes a pH-induced structural transition which is consistent with the presence of a duplex with C·A+ base pairs at acidic pH. Our crystal structure provides a first glimpse of an RNA double helix based entirely on wobble base pairs with possible applications in RNA or DNA nanotechnology and pH biosensors.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
RNA de Cadeia Dupla
Idioma:
En
Revista:
RNA
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Alemanha