10 / 13
Page 46
allied
academies
Virol Res J 2017 Volume 1 Issue 3
International Virology Conference
October 30-31, 2017 | Toronto, Canada
T
he subviral pathogens known as viroids are composed of a
single stranded and circular RNA genome in the size range
of 246-401 nt. The 30 species known are causing a wide array
of symptoms to many plants. An important feature is their
non-coding genome. This has for consequence that they
depend on their sequence and structure to infect a host.
The classification of viroids based only on their sequence
was previously shown to be insufficient. To strengthen that
classification, we believe that the use of the secondary
structure of the viroids is useful. Generally, their structures
were predicted with thermodynamics-based RNA folding
programs, which were shown to lack precision for RNA longer
than 200 nt. Thus the predicted structure of a viroid needs
to have more information on its folding to produce accurate
models for interpreting any systematic studies. Following
the adaptation of SHAPE probing and computer assisted
structure prediction to the viroid, we have elucidated the
structure of all the known species. In fact, the structures
in solution for one variant of all
Avsunviroidae
members as
well as 30
Pospiviroidae
species have been elucidated. There
were many significant differences compared to predicted
structure in absence of probing data, confirming the
importance of this study. In addition to providing a complete
compendium of viroid structure, this analysis permitted to
ascertain structural motifs that could be important for their
biology and classification.
e:
Jean-Pierre.Perreault@USherbrooke.caA viroid structural compendium
Jean-Pierre Perreault
and
Tamara Giguère
Université de Sherbrooke, USA