Dissertation

Identification and characterization of viral Xrn1-resistant RNAs

Several single-stranded RNA viruses make use of Xrn1-resistant RNAs in their 3’ untranslated regions of their genome RNAs in order to increase their pathogenicity.

Author

Dilweg, I.W.

Date

22 March 2023

Links

Thesis in Leiden Repository

This thesis focuses on two types of Xrn1-resistant RNAs: those involving the “coremin” motif (xrRNAC) and those found in members of the Flaviviridae family (xrRNAF). While the structure for xrRNAFs has been solved, the xrRNAC structure is yet elusive. Therefore, we employed systematic mutational analysis in order to identify the features that are involved in halting the 5’-3’ exoribonuclease Xrn1 by xrRNAC. This led to the identification of novel variations of xrRNAC in viral families that were not yet known to employ an xrRNA. Regarding xrRNAF, we investigated their distribution and variability throughout the Flaviviridae family, and concluded that a universal xrRNAF structure is responsible for stalling Xrn1. Furthermore, the work in this thesis expands on the known, potential functions of xrRNAs by showing how xrRNAC is able to both inhibit scanning ribosomes and promote frameshifting.