A VERY POORLY EXPRESSED TRANSFER RNASER IS HIGHLY CONCENTRATED TOGETHER WITH REPLICATION PRIMER INITIATOR TRANSFER RNAMET IN THE YEAST TY1 VIRUS-LIKE PARTICLES

The analysis of the tRNAs associated to the virus-like particles produ ced by the Ty1 element revealed the specific packaging of three major tRNA species, in about equal amounts: the replication primer initiator tRNA(Met), the tRNA(Ser)AGA and a tRNA undetected until now as an exp ressed species in yeast. The latter tRNA is coded by the already descr ibed tDNA(Ser)GCT. This tRNA is enriched more than 150 fold in the par ticles as compared to its content in total cellular tRNA where it repr esents less than 0.1% (initiator tRNA(Met) and tRNA(Ser)AGA being 11 a nd 4 fold enriched respectively). This tRNA is the only species coded by the tDNA(ser)GCT gene which is found in three copies per genome sin ce no other corresponding expressed tRNA could be detected. This gene is thus very poorly expressed. The high concentration of tRNA(Ser)GCU in the particles compared to its very low cellular content led us to c onsider its possible implication in Ty specific processes.