A mouse tRNA pseudogene derived from a tRNA(Trp) coding sequence

The identification and characterization of a mouse tRNA(Trp) pseudogene is reported. A synthetic oligonucleotide (31 mer), identical with the 3' half of a tRNA(Trp), was used to examine three mouse lambda clones that are known to contain clusters of tRNA genes. A fragment of one of these lambda clones strongly hybridizes to the oligonucleotide; the sequence of this region shows the presence of a gene significantly homologous to the chick tRNA(Trp). However two point mutations and a three base deletion prevent the folding of a possible transcript of this gene. The presence of a conserved promoter sequence for RNA polymerase III, that should allow the transcription of this gene, does not ensure the transcription of the gene, at least in our in vitro system.