A mobile loop near the active site acts as a switch between the dual activities of a viral protease/deubiquitinase
Arabidopsis plants were mechanically inoculated with water, or in vitro transcripts as indicated. (A) Symptoms development were monitored and representative pictures of the symptoms observed on the inoculated leaves (upper panel) at 14 dpi and on the systemic leaves (lower panel) at 17 dpi are shown for each inoculum. The same type and severity of symptoms were consistently observed in at least four independent experiments involving n ≥ 26 plants. (B) The ability of the transcripts to multiply in systemic leaves was assessed by extracting total RNAs and quantifying viral genomic RNA by RTqPCR at 17 dpi. Viral RNA levels were calibrated and normalized to EF1α and 18S rRNA reference genes RNAs. The relative accumulation of viral mutant RNAs as compared to the WT TYMV RNA is represented as the mean +/- SD. Mean and SD values, as well as the number of samples (n) analyzed in at least three independent experiments are indicated below panel (B).