FIGURE 2.

Dimensions and groove shapes of DNA:RNA heteroduplexes as a function of the sugar pucker in the two strands. (A) The DNA and RNA adopting O4′-endo and C3′-endo conformation, respectively. Carbon atoms in DNA are colored in magenta and carbon atoms in RNA are colored in yellow. (B) Both, the DNA and RNA adopting C3′-endo conformation. Color scheme identical to panel (A). The van der Waals surfaces are shown in a semi-transparent mode and illustrate the narrower minor groove of the duplex with O4′-endo puckers of 2′-deoxyriboses. The models were generated with the program TURBO-FRODO (47).