Fig. 4.

C. albicans SerRS_Leu197 is catalytically more efficient. (A) Rates of serine activation by SerRS_Ser197 and SerRS_Leu197 in the presence and absence of tRNA. (B) Schematic representation of the C. albicans orthogonal pair coexpression system. (C) Relative growth rate variation of E. coli transformed with the C. albicans orthogonal pairs SerRS_Ser197/tRNA_CAG or shows that both isoforms induce serine misincorporation at CUG codons. Horizontal bars represent the observed/control growth rate ratio. The growth rate with is comparable to that of the negative control, indicating that C. albicans is not aminoacylated by the host SerRS. (D) Expression levels of SerRS isoforms quantified by infrared band intensities. (E) E. coli endogenous β-galactosidase activity upon coexpression of C. albicans . The ratio between the β-galactosidase activity for each orthogonal pair and that of controls expressing only SerRS is represented by a horizontal bar.^∗P < 1 × 10^-2; ^∗∗P < 1 × 10^-9.