During bacteriophage T7 infection, the Escherichia coli RNA polymerase β′ subunit is phosphorylated by the phage-encoded kinase Gp0.7. Here, we used proteolytic degradation and mutational analysis to localize the phosphorylation site to a single amino acid, Thr1068, in the evolutionarily hypervariable segment of β′. Using a phosphomimetic substitution of Thr1068, we show that pliosphorylation of β′ leads to increased ρ-dependent transcription termination, which may help to switch from host to viral RNA polymerase transcription during phage development.
All Science Journal Classification (ASJC) codes
- Molecular Biology