A novel suppressor tRNA from the dimorphic fungus Candida albicans

Unfractionated tRNAs from a number of prokaryotes and eukaryotes were examined for their ability to promote termination codon readthrough in a cell-free system isolated from Saccharomyces cerevisiae. tRNA from the dimorphic fungus Candida albicans was found to have significant UGA and UAG readthrough activity and this activity was present in tRNA extracted from both the yeast and the hyphal phase of the fungus. Unusually the efficiency of readthrough activity in vitro was not affected by the [psi] determinant. C. albicans tRNA was fractionated by one-dimensional and two-dimensional gel electrophoresis and both readthrough activities appeared to be associated with a single species of tRNA.