CPSF6 and infection: Similar to A105T, N74D allowed T54A to escape from inhibition by CPSF6-358 (Fig. 1A) and reduced binding of CA tubes to CPSF6 in vitro (Fig. S2) Moreover, N74D acted similarly to A105T as reported by Qi et al. [39] with respect to its ability to restore T54A infectivity in aphidicolin-arrested HeLa cells (Fig. 1D) and infection of actively proliferating HeLa cells (Fig. 1D).