Table 1. Parameters used for model building according to the geometry indicated in Fig. 2 ▶ .

The increment of the α_hi angle is dependent on the tilting angle β_hi and is calculated by dividing the circumference described by the end of the tilted helix by the helical spacing s as described in the methods.

	Coarse		Fine
	Range	Increment	Range	Increment
Inner
rh1 (Å)	8–14	2	9–11	1
αh1 (°)	0–360	s = 4.5 Å	90–130	s = 2 Å
βh1 (°)	0–45	7.5	20–40	2.5
Outer
αb (°)	0–72	7.2	10–25	2.5
rh2 (Å)	10–44	2	20–25	1
αh2 (°)	0–360	s = 4.5 Å	100–140	s = 2 Å
βh2 (°)	0–45	7.5	25–35	2.5