Figure 2.

Nonsense mutation in spr1178 and growth defect in penicillin-resistant S. pneumoniae. (a) The growth kinetics of S. pneumoniae R6 wild-type, S. pneumoniae R6^{SmR, 2x2b1a-M2} and S. pneumoniae R6^{SmR, 2x2b1a, spr1178-M2} was followed by measuring the optical density of the cultures every hour for a 20-hour period. (b) The reversion of the spr1178 nonsense mutation to a wild-type sequence decreased the growth defect of the R6M1 mutant. Results are the average of at least three independent measurements.