Fig. 6.

Key amino acid variations of EV71 3C^pro affect its ability to cleave OAS and 3AB. A HEK293T cells were cotransfected with OAS3 and EV71-3C, CVB3–3C or CA16-3C expression plasmids as indicated for 48 ​h. The protein levels of exogenous OAS3 and 3C in cell lysates were examined by Western blot. B HEK293T cells were cotransfected with OAS3 and EV71-3C, EVD68-3C or CA6-3C expression plasmids as indicated for 48 ​h. The protein levels of exogenous OAS3 and 3C in cell lysates were examined by Western blot. C Sequence alignment of 3C proteases derived from five representative enterovirus subtypes revealed that amino acids Ile36, Val86, and Ile157 were unique in CA16 3C compared with the other four enterovirus subtypes. D HEK293T cells were cotransfected with OAS3 and WT, mutants of EV71-3C, or CA16-3C expression plasmids as indicated for 48 ​h. The protein levels of exogenous OAS3 and 3C in cell lysates were examined by Western blot. E HEK293T cells were cotransfected with OAS1 and WT or mutants of EV71-3C expression plasmids as indicated for 48 ​h. The protein levels of exogenous OAS1 and 3C in cell lysates were examined by Western blot. F HEK293T cells were cotransfected with OAS2 and WT or mutants of EV71-3C expression plasmids as indicated for 48 ​h. The protein levels of exogenous OAS2 and 3C in cell lysates were examined by Western blot. G HEK293T cells were cotransfected with 3AB and WT or mutants of EV71-3C expression plasmids as indicated for 48 ​h. The protein levels of exogenous 3AB and 3C in cell lysates were examined by Western blot.