Table 3.1. Effect of local conformational coupling on the lowest-frequency normal twisting mode of a 100 bp generic DNA homopolymer^*.

Coupled variables	${\nu }_1^0$† (cm-1)	${\nu }_1^{\mathrm{eq}}$† (cm-1)	ΔC§ (%)
	0.186	0.186
Tilt-Roll	0.186	0.186	0.0
Tilt-Twist	0.185	0.185	-0.5
Tilt-Shift	0.186	0.186	0.0
Tilt-Slide	0.186	0.186	0.0
Tilt-Rise	0.186	0.186	0.0
Roll-Twist	0.192	0.193	8.6
Roll-Shift	0.186	0.186	0.0
Roll-Slide	0.186	0.186	0.0
Roll-Rise	0.186	0.186	0.1
Twist-Shift	0.185	0.185	-0.6
Twist-Slide	0.185	0.186	0.0
Twist-Rise	0.182	0.193	8.2
Shift-Slide	0.186	0.186	0.0
Shift-Rise	0.186	0.186	0.0
Slide-Rise	0.186	0.186	0.0
Roll-Twist,Twist-Rise	0.188	0.210	28.3
Twist-Slide,Twist-Rise	0.181	0.199	14.7
Roll-Twist,Twist-Slide	0.194	0.198	13.6
Roll-Twist,Twist-Slide,Twist-Rise	0.184	0.214	33.1

^*Dimeric rest state: $({\theta }_1^0,{\theta }_2^0,{\theta }_3^0,{\theta }_4^0,{\theta }_5^0,{\theta }_6^0)=(0°,2.8°,33.8°,0\mathrm{Å},-0.20\mathrm{Å},3.33\mathrm{Å})$.

^†Frequencies of DNA chains subject to the following global constraints: ${\nu }_1^0$, unrestrained chain ends; ${\nu }_1^{eq}$, ends restrained to equilibrium length.

^§Change in torsional modulus of the restrained duplex subject to given conformational coupling compared to that (C = 1.98 × 10^-19 erg-cm) of the unrestrained, generic molecule with independent fluctuations of base-pair step parameters.