The relative hybrid duplex structure of DNA and RNA is greatly influenced by primary sequence composition. The primary sequence dictates duplex structure and stability, giving DNA a B-type helix, RNA an A-type helix and DNA:RNA a mixed A:B type helix as illustrated below. Based on the structural and thermodynamic study of DNA and RNA duplexes, rationalize which type of hybrid duplexes form the most stable structures and describe experimental methods that can be used to characterize i. duplex stability and ii. duplex structure. Relative thermodynamic stability of DNA, RNA, and DNA:RNA hybrid duplexes: relationship with base composition and structure.
a) dsRNA.
b) dsDNA.
c) dNA-RNA.