Fig. 3.

Genetic suppression of $pyrE{\mathit{2}}_{am}$ in H. volcanii H1424. Cells were transformed with (A and C) a mixture of plasmids pTA1228.$\text{pyrE}{2}_{\text{am}}$ and $\text{pMLH}.\mathrm{\beta }{\text{-}\mathrm{gal}}_{\text{am}}.{\text{tRNA}}_{\mathrm{am}}^{\mathrm{Ser}}i$ or (B) a mixture of plasmids pTA1228.$\text{pyrE}{2}_{\text{am}}$ and $\text{pMLH}.\mathrm{\beta }{\text{-}\mathrm{gal}}_{\text{WT}}.{\text{tRNA}}_{\mathrm{WT}}^{\mathrm{Ser}}i$. Transformants were selected directly on Hvo-Ca medium supplemented with 3 mM tryptophan (Trp) as indicated.