[Effect of restricting the action of an amber-mutation suppressor contained in bacteriophage T4 genome].

The action of a bacteriophage suppressor can be restricted due to mutations arising in the genome of the host bacteria. Bacterial strains Escherichia coli BN and CAN were isolated in which a complete restriction of the action of phage suppressor psu+ took place. In thees strains obtained the restriction of serin-specific phage suppressors psu + a and psu + b is brought about. The action of bacteriophage suppressor su3+ containing in E. coli CAN is not abolished in this strain. The abolish of the action of glutamine-specific phage suppressor in both strains is not realized. Thus, in bacterial strains of E. coli BN and CAN the restriction of action of only definite tRNA type takes place. Mutation alterations in the bacterial strains obtained can be due to the change of 1) ribosomes, 2) aminoacyl-tRNA-synthetase, 3) suppressor tRNA. In this case the possibility of mutation alterations in the gene controlling the synthesis of suppressor tRNA is excluded, but there is a possibility of changing the tRNA molecule itself during maturation.