Nonlethal nonsense mutations obtained earlier in the essential gene SUP45 encoding the
translation termination factor eRF1 in the yeast Saccharomyces cerevisiae were further
characterized. Strains carrying these mutations retain the viability, since the full-length eRF1
protein is present in these strains, although in decreased amounts as compared to wild-type
cells, together with a trucated eRF1. All nonsense mutations are likely to be located in a
weak termination context, because a change in the stop codon UGAA (in the case of …

Nonlethal nonsense mutations obtained earlier in the essential gene SUP45 encoding the
translation termination eRFI factor in the yeast Saccharomyces cerevisiae were further
characterized. Strains carrying these mutations retain the viability, since the full-length eRF1
protein is present in these strains, although in decreased amounts as compared to wild-type
cells, together with a truncated eRF1. All nonsense mutations are likely to be located in a
weak termination context, because a change in the stop codon UGAA (in the case of …