Bonilla, S. | bioRxiv Science

bioRxiv2020

A structured viral RNA uses molecular mimicry and conformational dynamics to coordinate multiple functions

Viruses require multifunctional structured RNAs to hijack their hosts biochemistry, but their mechanisms can be obscured by the difficulty of solving conformationally dynamic RNA structures. Using cryo-EM, we visualized the structure of the mysterious viral tRNA-like structure (TLS) from brome mosaic virus (BMV), which affects replication, translation, and genome encapsidation. Structures in isolation and bound to tyrosyl-tRNA synthetase (TyrRS) show that this [~]55 kDa purported tRNA mimic undergoes large conformational rearrangements to bind TyrRS in a form that differs dramatically from tRNA. Our studies reveal how viral RNAs can use a combination of static and dynamic RNA structures to bind host machinery through highly noncanonical interactions and highlights the utility of cryo-EM for visualizing small conformationally dynamic structured RNAs.

biophysics↗

bioRxiv2020

Mapping the impacts of hurricanes Maria and Irma on banana production area in the Dominican Republic

Extreme weather events can have devastating impacts on agricultural systems, and the livelihoods that depend on them. Tools for rapid, comprehensive and cost-effective assessment of impacts, especially if carried out remotely, can be of great value in planning systematic recovery of production, as well as assessing risks from future events. Here, we use openly available remote sensing data to quantify the impacts of hurricanes Irma and Maria in 2017 on banana production area in the Dominican Republic -- the worlds largest producer of organic bananas. Further, we assess the risk to current production area if a similar extreme event were to re-occur. Hurricane associated damage was mapped using a simple change detection algorithm applied to Synthetic Aperture Radar (SAR) data over the three main banana growing provinces of northern Dominican Republic, i.e. Monte Cristi, Valverde and Santiago. The map of hurricane affected area was overlaid with banana plantation distributions for 2017 and 2019 that were mapped (accuracy = 99.8%) using a random forest classifier, and a combination of SAR and multi-spectral satellite data. Our results show that 11.35% of banana plantation area was affected by hurricane damage in 2017. Between 2017 and 2019, there was a high turnover of plantation area, but with a net gain of 10.8%. However, over a quarter (26.9%) of new plantation area spatially overlapped with regions which had seen flooding or damage from hurricanes in 2017. Our results indicate that banana production systems in northern Dominican Republic saw extensive damage in the aftermath of hurricanes Irma and Maria. While production area has recovered since then, a substantial proportion of new plantations, and a greater fraction of production area in general, occur at locations at risk from future extreme events.

ecology↗