Fig. 1: Definition of terms describing pairs between nucleobases in various orientations.
From: A folding motif formed with an expanded genetic alphabet
a, Canonical Watson–Crick pair joining antiparallel strands between dZ and dP, with deoxyribose or ribose (R, labelled pink) oriented down. b, Reverse Watson–Crick pair between dZ and dJ, with the 2′-deoxyribose (R) on the left (right) oriented down (up), holding together parallel strands. c, Skinny pair between dZ and dS, with both 2′-deoxyriboses (R) oriented down, holding together antiparallel strands. d, Reverse skinny pair between dZ and dC; the 2′-deoxyribose (R) on the left (right) is oriented down (up). e, Positively charged reverse skinny pair between charge-neutral and protonated C; the 2′-deoxyribose (R) on the left (right) is oriented down (up). f, Negatively charged reverse skinny pair between charge-neutral and deprotonated Z; the 2′-deoxyribose (R) on the left (right) is oriented down (up).
