Identification of a short, highly conserved, motif required for picornavirus capsid precursor processing at distal sites - Fig 9

Model: Potential role of chaperone binding to a conserved motif for correct capsid precursor folding a) Hsp90 (or other chaperones and co-chaperones) is believed to bind to the P1-2A precursor (or P1 for enteroviruses) to facilitate folding into a state where the 3Cpro (or 3CDpro) is able to process the precursor to the mature structural capsid proteins prior to particle assembly. b) It is hypothesized that the conserved motif, YCPRP, in the C-terminus of VP1 is required for the binding of a chaperone (or co-chaperone). In the absence of this interaction, the precursor will be incorrectly folded and hence 3Cpro (or 3CDpro) will not recognize the cleavage sites; the misfolded, intact, precursor will be degraded by the proteasome.