E.Lescrinier
et al.
(2010).
Structure determination of the top-loop of the conserved 3'-terminal secondary structure in the genome of flaviviruses.
Chembiochem,
11,
1404-1412.
PubMed id: 20540055
To what extent small differences in RNA sequences (mutations) can have a
profound impact on biology remains an intriguing question. This effect can be
studied by using untranslated RNA regions as a model. We have studied the
influence of mutations on the structure of an RNA hairpin that occurs in the
3'-untranslated region (UTR) of Flaviviridae, and is known to have a large
impact on the vector dependency of flaviviruses. Three related RNA sequences
were studied by NMR spectroscopy. The selected sequences represent each one of
the three clusters in the flavivirus genes (mosquito-borne, tick-borne, and
no-known-vector viruses). A new strategy was used to obtain chemical shift
signatures of carbonyl atoms in unlabeled uridine nucleobases to characterize
their involvement in hydrogen bonding. Clear differences occur in the structures
and stacking pattern of the three RNA hairpins. The observed differences cannot
be predicted based on sequence analysis. A different biology can be correlated
with a different RNA tertiary structure. The underlying biological mechanism,
however, remains to be studied.