Structure-based identification of functional residues in the nucleoside-2'-O-methylase domain of Bluetongue virus VP4 capping enzyme

Stewart, Meredith E.; Roy, Polly

The differences in the development and size of the plaques of the mutant viruses were also reflected in the titres and growth kinetics monitored over 96 h (Fig. 7B) . The Y334A mutant virus followed a growth pattern similar to that of the WT virus; similar titres were observed at all time-points measured indicating no apparent effect on virus replication. However, the other three mutant viruses, N311A, R367A and NYR, had titres lower than the WT virus (1-3.5 log 10 ), the R367A mutant virus titres were consistently 1 log 10 lower than WT at each time point. For the first 24 h p.i., the growth of the N311A followed a pattern similar to both the WT and Y334A mutant viruses in BSR cells. However, after 24 h p.i., the growth curve of the N311A mutant virus plateaued with titres between 1 log 10 to 1.5 log 10 lower than WT. The growth of the NYR mutant virus within the first 24 h p.i. was slower than all three single mutant viruses and the WT and as observed with the N311A virus, growth curve plateaued after 24 h p.i. The NYR mutant virus consistently had titres of 2.5-3.5 log 10 lower than WT (Fig. 7B) .