Figure 3
CUG ambiguity in vivo in Candida albicans in different environmental conditions. Quantification of CUG ambiguity in vivo was carried out using a reporter protein that contained a CUG codon cassette and a poly(His)6 tag. (a,b) Leucine mis-incorporation at the CUG position was determined in white cells at 30°C, 37°C, in pH 4.0, in 1.5 mmol/l hydrogen peroxide (H2O2), and ranged from 2.96 ± 0.49%, 3.9 ± 0.64%, 4.95 ± 1.14% to 4.03 ± 0.71%, respectively. C. albicans white cells were used because opaque cells are very rare and under normal growth conditions only white cells are found in culture. P values were determined using the Scheffe test and are as follows: *P = 0.048 and **P = 0.0017. (c,d) Mass spectrum of the reporter protein purified from C. albicans cells expressing the Saccharomyces cerevisiae tRNACAGLeu, showing that 28.1% ± 1.17 of the peptides incorporated leucine and 71.9% ± 1.17 incorporated serine at the CUG codon position. P value is as follows; *P ≈ 0.