Modification of the suppressor phenotype of thymine requiring strains ofEscherichia coli

Abstract

Thymine requiring strains of Escherichia coli suppress nonsense and frameshift mutations during translation. Strains with different genetic backgrounds exhibited different nonsense suppression spectra and showed differences in the apparent suppression efficiency. Part of this strain difference is due to a presumably novel gene {tsmA) mapping near 39 min. This gene affects the spectrum and apparent efficiency of suppression, and appears to affect the utilization of thymidine.