D-tyrosyl-tRNA(Tyr) metabolism in Saccharomyces cerevisiae.
The Saccharomyces cerevisiae YDL219w (DTD1) gene, which codes for an amino acid sequence sharing 34% identity with the Escherichia coli D-Tyr-tRNA(Tyr) deacylase, was cloned, and its product was functionally characterized. Overexpression in the yeast of the DTD1 gene from a multicopy plasmid increased D-Tyr-tRNA(Tyr) deacylase activity in crude extracts by two orders of magnitude. Upon disruption of the chromosomal gene, deacylase activity was decreased by more than 90%, and the sensitivity to D-tyrosine of the growth of S. cerevisiae was exacerbated. The toxicity of D-tyrosine was also enhanced under conditions of nitrogen starvation, which stimulate the uptake of D-amino acids. In relation with these behaviors, the capacity of purified S. cerevisiae tyrosyl-tRNA synthetase to produce D-Tyr-tRNA(Tyr) could be shown. Finally, the phylogenetic distribution of genes homologous to DTD1 was examined in connection with L-tyrosine prototrophy or auxotrophy. In the auxotrophs, DTD1-like genes are systematically absent. In the prototrophs, the putative occurrence of a deacylase is variable. It possibly depends on the L-tyrosine anabolic pathway adopted by the cell.
Soutourina
J
J
Laboratoire de Biochimie, Unité Mixte de Recherche No. 7654, CNRS-Ecole Polytechnique, 91128 Palaiseau Cedex, France.
Blanquet
S
S
Plateau
P
P
D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015723:Gene Library; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012365:RNA, Transfer, Tyr / Q000235:genetics* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012984:Software; D014443:Tyrosine / Q000378:metabolism; D014448:Tyrosine-tRNA Ligase / Q000378:metabolism
D012365:RNA, Transfer, Tyr; D014443:Tyrosine; D014448:Tyrosine-tRNA Ligase