Table 1.

Membrane parameters and their values

Parameter	Variable	Experimental estimate	Source	Model value
fd-Y21M half-length	$l_{\text{𝑓𝑑}}$	430 nm	(18)*	Same
M13KO7 half-length	$l_{\text{M}13}$	560 nm	(18)*	Same
Virus half-length difference	$d$	130 nm	$l_{\text{M}13}-l_{\text{𝑓𝑑}}$	Same
Virus diameter		7 nm	(18)
Virus nearest-neighbor distance	$\xi$	12 nm	(19)	Same
Virus 2D concentration	$c_{\text{v}}$	$\sim$9,000 $\mathrm{\mu }{\text{m}}^{-2}$	$1/\pi {(\xi /2)}^2$	8,500 $\mathrm{\mu }{\text{m}}^{-2}$
fd-Y21M Frank constant	$K_{\text{𝑓𝑑}}$	$\sim$2 pN	(1)†,‡	4 pN
M13KO7 Frank constant	$K_{\text{M}13}$	$\sim$4 pN	(6)‡	10 pN
fd-Y21M twist wavenumber	$q_{\text{𝑓𝑑}}$	$\sim$0.1 $\mathrm{\mu }{\text{m}}^{-1}$	(7)‡	0.11 $\mathrm{\mu }{\text{m}}^{-1}$
M13KO7 twist wavenumber	$q_{\text{M}13}$	$\sim$ − 0.5 $\mathrm{\mu }{\text{m}}^{-1}$	(6)‡	− 0.55 $\mathrm{\mu }{\text{m}}^{-1}$
fd-Y21M birefringence	$\mathrm{\Delta }{n}_{\text{𝑓𝑑}}$	$\sim 0.008$	(8)†,§	$0.011$
M13KO7 birefringence	$\mathrm{\Delta }{n}_{\text{M}13}$	$\sim 0.008$	(8)†,§	$0.011$
Dextran concentration	$c$	48,000 $\mathrm{\mu }{\text{m}}^{-3}$	(18)	Same
Dextran radius	$a$	$\sim$25 nm	(23–25)¶	Same
Temperature	$T$	22 °C	(18)	Same

^*Half the end-to-end length estimated from contour lengths and persistence lengths.

^†Measured for fd-wt virus.

^‡Imprecise estimates extrapolated to membrane virus concentration $\sim$200 mg $\cdot$ mL^{− 1} (corresponding to $c_{\text{v}}\sim$ 9,000 $\mathrm{\mu }{\text{m}}^{-2}$) based on concentration-dependent behavior of fd-wt suspensions (1).

^§Assuming membrane nematic order parameter of 1 and virus concentration $\sim$200 mg$\cdot$mL^{− 1} (corresponding to $c_{\text{v}}\sim \mathrm{9,000}\hspace{0.17em}\mathrm{\mu }{\text{m}}^{-2}$).

^¶Hydrodynamic radii for dilute solutions of 500 kDa dextran, whereas our experiments are in the semidilute regime.