FIG. 2.

Transcriptional ability of glutamic acid-substituted P mutants. In vitro transcription reconstitution was carried out using 0.2 μg N-RNA template, 0.1 μg of recombinant P protein, and ≈1.0 μg of cytoplasmic extract from Sf21 cells expressing the L protein. mRNAs were processed as described above and separated on a 5% polyacrylamide gel containing 8 M urea. P0 stands for bacterially expressed unphosphorylated P wild-type. The various mutants are P3E (Ser60, Thr62, and Ser64 mutated to Glu), P60E/62E (Ser60, Thr62 mutated to Glu), P62E/64E (Thr62, Ser64 mutated to Glu), P60E/64E (Ser60, Ser64 mutated to Glu). P60, P62E, and P64E are single mutants in which Ser60, Thr62, or Ser64 is mutated to Glu, respectively.