Poster abstracts
Poster number 125 submitted by Md Sharear Saon
Roles for Charged and Tautomeric Nucleobases in RNA Structure
Md Sharear Saon (Department of Chemistry, Center for RNA Molecular Biology, Pennsylvania State University), Andrew J. Veenis (Department of Chemistry, Center for RNA Molecular Biology, Pennsylvania State University), Catherine A. Douds (Center for RNA Molecular Biology, Department of Biochemistry and Molecular Biology, Pennsylvania State University), Alexander C. Williard (Department of Chemistry, Center for RNA Molecular Biology, Pennsylvania State University), Neela Yennawar (Huck Institutes of the Life Sciences, Pennsylvania State University), Philip C. Bevilacqua (Department of Chemistry, Center for RNA Molecular Biology, Department of Biochemistry and Molecular Biology, Pennsylvania State University)
Abstract:
A pressing question is whether RNA can adopt novel protonation and tautomeric states. These could increase RNA function in extant life and diversify RNA in the origins of life. Depending on context and environmental conditions, RNA may be able to modify its four nucleotides non-covalently and thereby adopt diverse folds and functions. To date, covalent modifications of RNA have received widespread attention, but much less is known about non-covalent modifications of RNA. Non-covalently modified nucleotides can be classified into charged and tautomeric forms, which involve changes in protonation state and proton location. These non-covalently modified nucleotides may provide additional stability with the formation of non-Watson-Crick base pairs and provide insights into unique regions in RNA molecules. We used a cheminformatic approach to study these non-covalent changes to the bases. We propose two novel orientations of G•U wobble base pairs, which require either G or U to be negatively charged or to form tautomers. We provide computational analysis of proposed rare G•U wobble within the solved RNA 3D structures deposited in the Protein Data Bank. These rare wobbles enhance the function of RNA, possibly providing a source to mutagenesis in copying the genetic code both in extant life and on the early Earth and throughout the Universe.
Keywords: Non-covalent modifications of RNA, Rare wobble base pairs, Tertiary structure of RNA