Figure 2. prkaca-L173A and prkaca-F327A cannot support viability in a tpk null strain.

Point mutations were introduced at the nucleotide binding sites indicated in Figure 1B . Coexpression of wild-type and mutant alleles of PKA is demonstrated on Leu-Ura- selection plates. Expression of the mutants alone is shown on 5-FOA plates. All mutants tested, except prkaca-L173A and prkaca-F327A, were viable at permissive and elevated temperatures.