Roles for charged bases and tautomers in RNA and DNA structure  

Abstract:  RNA and DNA are comprised of only four, similar 
side-chains.  This simplicity has the potential to limit the 
functional and therefore biological diversity of RNA and DNA.  
While the importance of covalent modifications of RNA and DNA 
are widely known and appreciated, non-covalent modifications 
such as protonation and deprotonation events, as well as 
prototropic shifts, are less known.  I will present evidence 
for the importance of such states in RNA and DNA, and describe 
efforts to define the diversity and extent of such motifs 
in vivo by a combination of chemiinformatic approaches and 
genome-wide chemical probing approaches.