S.S. Wijmenga, B.N.M. van Buuren/Progress in Nuclear Magnetic Resonance Spectroscopy 32(1998)287-387 A HS HS"H4H3'H2 H2"HI H8 NH2 NH [ NH2 HS H6 HI H2" F H3'H4'H5"H5' HS"" H3 H2H2" H6 CH3 NH NH2 H2 H8 8HEB2田HB H5H5”H4H3H2"H2 CH3NH NH2 H2 H8 HI' H2"H2H H3" H4 H5" HSA HSHS"H4'H3'H2'H2 中中 H2'H3'H4'HS"H5 HSHS"H4'H3'H2'H2" 6 HS NH2JNH NH2 H8 HI H2"H2 H3 H4 HS"HS HSH5H4H3H2'H2HI H6 CH3 NHNH2 H2 H8 HI H2"H2 2" H3 H4 HS"HSA HS'H5"H4 H2"HI HS H2 NH2]NH CH3 H6 HI"" H3"H4 H5"H5 H5 HS"H4 H3 H2 H2"HI H6 HS NH2NH NH2 H8 HI H2"H2 H4 HS"HS HS HS" H4' H3 H2H2"HI H8 H2 NH2 NH CH3 H6 HI H2"H2 H3 H4 HS"HS" 田FHHH田HNH2 H CH H6 HI H2H2 H3 H4H5H5 EHm业正mcm[N正正EE时3 HS HS" H4 H3" H2 H2" HI HB NH2 NH NH2 HS H6 HI H2"H2 H3" H4 HS"H5 IHS HS" H4 H3 HZ H2 HI H8 NH2 NH NH2 H5 H6 HI' H2H2. H3' H4' H5" H5' HS H5"H4 H3 H2 H2"HI'H8 H2 NH2 NH CH3 H6 HI H2"H2 H3 H4 HS"H H5 H5 H4 H3 H2H2"HI H8 NH2 NH NH2 HS H6 HI H2" H2 H3" H4 H5"H5 H5’H5”H4H3′H2′H2"H′H8NH2NH 12 H5 H6 HI'H2H2'H3'H4'H5"H5 5 3 base stacking in A-DNA(A), B-DNA(B)and RNA(C). The meaning of the symbols is: 0-2.5 A( thick solid line), 2.5-3.0 A(solid line ), 3.0-4.0 A(dashed line), 4.0-50A (dotted line)Fig. 2. Overview of short sequential and inter-strand proton–proton distances for all possible combinations of base stacking in A-DNA (A), B-DNA (B) and RNA (C). The meaning of the symbols is: 0–2.5 A˚ (thick solid line), 2.5–3.0 A˚ (solid line), 3.0–4.0 A˚ (dashed line), 4.0–5.0 A˚ (dotted line). 296 S.S. Wijmenga, B.N.M. van Buuren/Progress in Nuclear Magnetic Resonance Spectroscopy 32 (1998) 287–387