Figure 1.

Growth curves of Trt1p mutants. Precultures inoculated with colonies after plasmid shuffle were grown in YES liquid media containing geneticin at 32°C for 24 h. Each day thereafter, liquid cultures were inoculated at a density of 5 × 10⁴ cells/ml, grown at 32°C for 24 h, and the cells were counted. Those cells not used for inoculation were harvested by centrifugation and were stored frozen for DNA preparations. For every mutant, at least two growth curves from independent colonies were recorded. In the case of F444A, the one curve showing a growth defect was subsequently found to be caused by a second-site two-amino acid deletion in Trt1p, whereas those cells carrying only the F444A mutation grew normally. The positions of the mutations in the T-motif and in the RT-domain of Trt1p are indicated in the diagram.