Poster abstracts
Poster number 146 submitted by Fiona Tillyer
Structural and Enzymatic Characterization of PUS4 Homologs
Fiona Tillyer (Chemistry, University of Michigan), Amelia Cochran (Chemistry, University of Michigan), Markos Koutmos (Chemistry, University of Michigan), Kristin Koutmou (Chemistry, University of Michigan)
Abstract:
Pseudouridine synthases (PUS) are a class of enzymes that catalyze the post-transcriptional isomerization of the nucleotide Uracil (U) into Pseudouridine (Ψ). The presence and impact of Ψ have been extensively studied, and it has long been known that this modification exists within all forms of non-coding RNA. Within the past decade, studies have shown that a subset of enzymes within the broad PUS family also modify mRNA, specifically the PUS7 and PUS4 enzymes in eukaryotes. The effect of Ψ on coding RNA and its potential impact on gene expression are now actively being studied, along with the factors that govern the substrate scope of PUS4 and PUS7. Currently, only one solved structure of a eukaryotic PUS4 enzyme is available, which limits our understanding of whether structural motifs exist across multiple organisms and how the enzyme functions broadly. Additionally, this existing structure is protein only, meaning there is room to solve structures including bound RNA substrates as well. Our research aims to structurally analyze a variety of PUS4 constructs from different organisms via X-ray crystallography. We then hope to use this information to gain a deeper understanding of how this enzyme binds its RNA substrates and performs its catalytic function.
Keywords: Pseudouridine, X-ray crystallography, RNA-binding proteins