Structure 116d 117d 118d 137d 160d 172d 189d 197d 1d78 1d82 1d93 1dc0 1dn6 1dnz 1g00 1m77 220d 232d 243d 257d 260d 281d 295d 2d47 2d94 317d 321d 348d 382d 395d 396d 399d 3ana 414d 440d 9dna RMSd(A) RMSd(B) RMSd(A) RMSd(B) 1.1 1.2 1.6 1.5 1.4 1.5 1.5 1.2 1.3 1.6 1.5 2.5 1.8 1.4 1.0 1.4 1.3 2.6 1.6 1.1 1.2 1.2 1.5 1.5 1.9 1.5 1.6 1.4 1.1 1.2 1.3 2.7 1.3 1.5 1.4 1.7 5.7 5.6 2.6 4.7 4.9 3.2 2.7 3.7 3.0 2.6 2.7 4.0 3.7 4.5 2.3 5.1 4.6 4.1 2.5 2.5 4.7 3.1 2.7 6.2 2.7 2.7 5.1 4.7 4.6 4.8 4.6 6.8 3.3 4.4 4.9 2.7 3.8 4.3 3.0 3.4 3.6 3.4 2.6 2.6 3.0 3.1 2.9 4.4 3.6 4.0 2.4 3.5 3.3 4.2 3.0 2.4 3.7 2.6 3.1 4.1 2.8 2.8 4.3 3.8 3.6 3.5 3.9 3.5 3.6 3.6 3.5 3.0 3.5 2.7 1.9 2.8 2.6 1.6 2.4 2.2 1.9 2.1 2.5 3.1 2.7 2.4 1.3 2.5 2.9 2.3 2.0 1.3 2.3 2.3 2.0 2.7 1.8 2.5 2.5 2.1 2.6 2.3 2.3 4.1 2.7 2.97 2.93 2.00 Table S1. RMSd (in Å) from canonical A and B forms obtained from (LEFT columns, in roman) canonical A/B conformations and the last 100 ps of parmbsc0 MD simulations (RIGHT columns in italics) for 36 A-DNAs in the Nottingham database. -1- LEGENDS TO SUPPLEMENTARY FIGURES Figure S1.Bidimensional error profiles (LMP2 as reference) in the α/γ map for the Npuckering. Relative energies are in kcal/mol and degrees. Figure S2. Selected monodimensional profiles in relevant regions of the α/γ map for both North and South puckerings. Yellow: parmbsc0, blue: LMP2, pink: DFT. Figure S3. Variation in the widhts of the grooves (TOP) and BI/BII transitions (BOTTOM) in parm94 (orange) and parm99 (magenta) MD simulations. Experimental values are marked in solid with their associated standard deviation as dashed lines (black: X-ray; red: NMR). Figure S4. Variation in the total number of hydrogen bonds in two independent 200 ns MD simulations of DD (green and blue) using parmbsc0. The maximum number of canonical hydrogen bonds for this structure is 26 (see Table 4). Figure S5. Variation of twist with the sequence as determined in parm94 (orange) and parm99 (magenta) simulations. The average values obtained by taking all NMR (red) or X-ray (black) structures for this sequence are shown as reference. Figure S6. Distribution of the backbone torsions during MD simulations of DD (parmbsc0 in green and parm99 in red) compared with the distribution of values in experimental databases of B-DNA (in blue). Figure S7. Distribution of helical parameters during MD simulations of DD (parmbsc0 in green and parm99 in red) compared with the distribution of values in experimental databases of B-DNA (in blue). Figure S8. Evolution of α/γ pairs for the 8 central basepairs of DD during one 200 ns parmbsc0 simulation. Alfa is magenta (strand I) and yellow (strand II), gamma is blue (strand I) and green (strand II). Figure S9. Distribution of different average helical basepair step parameters in parmbsc0 simulations of Nottingham’s database of B-DNAs. Displacements are in Å and angles in degrees. Figure S10. Evolution along time of different structural parameters in parmbsc0 simulations of DD-RNA (panel A) and a RNA duplex rich in mismatches (URL064; panel B). Figure S11. Evolution along time of different structural parameters in parmbsc0 simulations of a RNA-pseudoknot (UR0004). Figure S12. Evolution along time of rmsd to experimental structure (TOP), average twist (MIDDLE) and average groove width (BOTTOM) in parmbsc0 simulations of parallel stranded G-DNA. Figure S13. Evolution along time of rmsd to experimental structure (TOP) and average groove width (BOTTOM) in parmbsc0 simulations of antiparallel G-DNA.. -2- Figure S14. Parmbsc0 simulations of antiparallel triplex based on the d(A-A·T) motif. TOP: Evolution along time of rmsd: to X-ray structure using common backbone atoms (green) and to average structure using all atoms (black). MIDDLE: Evolution of average twist along time. BOTTOM: Evolution of groove width along time (brown: major-major groove; blue: minormajor groove; magenta: minor groove). Figure S15. Parmbsc0 simulations of antiparallel triplex based on the d(G-G·C) motif. TOP: Evolution along time of rmsd: to X-ray structure using common backbone atoms (green) and to average structure using all atoms (black). MIDDLE: Evolution of average twist along time. BOTTOM: Evolution of groove width along time (brown: major-major groove; blue: minormajor groove; magenta: minor groove). Figure S16. Parmbsc0 simulations of parallel triplex based on the d(T·A-T) motif. TOP: Evolution along time of rmsd: to X-ray structure using common backbone atoms (green) and to average structure using all atoms (black). MIDDLE: Evolution of average twist along time. BOTTOM: Evolution of groove width along time (brown: major-major groove; blue: minormajor groove; magenta: minor groove). Figure S17. Evolution along time of rmsd to experimental (green) and average (black) (TOP), average twist (MIDDLE) and average groove width (BOTTOM) in parmbsc0 simulations of ZDNA. Figure S18. Evolution along time of different helical parameters in parmbsc0 simulations of antiparallel Hoogsteen duplex DNA. Figure S19. Evolution along time of different helical parameters in parmbs0 simulations of DNA·RNA hybrid. RMSd: yellow: VS NMR, blue: VS Aform, pink: VS Bform. Figure S20. Distribution of the time needed to achieve RMSd(B)<RMSd(A) in 36 simulations of duplex DNA starting from the A-type experimental conformation (Nottingham’s database of A-DNAs). -3- Figure S1 -4- Figure 2 -5- Figure S3 -6- Figure S4 -7- Figure S5 -8- Figure S6 -9- Figure S7 - 10 - Figure S8 - 11 - Figure S9 - 12 - Figure 10. - 13 - Figure S11 - 14 - Figure S12 - 15 - Figure S13 - 16 - Figure S14 - 17 - Figure S15 - 18 - Figure S16 - 19 - Figure S17 - 20 - Figure S18 - 21 - Figure S19 - 22 - Figure S20 - 23 -