Table 1.

Structural parameters and charge density of dsDNA (B-form), dsRNA, and tsDNA

Parameter	B-DNA	dsRNA	tsDNA
Helical pitch (Å)	33.8	30.9	38.4
Number of basepairs per helical turn	10	11	12
Groove half-width (rad/π)	0.4, 0.6	0.64, 0.36	0.36, 0.35, 0.29
Radius at the center of phosphate groups (Å)	9	8.5	9.5
Axial distance per elementary charge, lc (Å)	1.7	1.4	1.1
Average surface charge density of phosphates, σ (μC/cm2)	17	21	25