Journal
MOLECULAR AND CELLULAR BIOLOGY
Volume 26, Issue 2, Pages 438-447Publisher
AMER SOC MICROBIOLOGY
DOI: 10.1128/MCB.26.2.438-447.2006
Keywords
-
Categories
Funding
- NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES [R01GM068854, R01GM029480] Funding Source: NIH RePORTER
- NIGMS NIH HHS [R01 GM 68854, R01 GM068854, R01 GM 29480, R01 GM029480] Funding Source: Medline
Ask authors/readers for more resources
The reassignment of stop codons is common among many ciliate species. For example, Tetrahymena species recognize only UGA as a stop codon, while Euplotes species recognize only UAA and UAG as stop codons. Recent studies have shown that domain I of the translation termination factor eRF1 mediates stop codon recognition. While it is commonly assumed that changes in domain 1 of ciliate eRF1s are responsible for altered stop codon recognition, this has never been demonstrated in vivo. To carry out such an analysis, we made hybrid proteins that contained eRF1 domain I from either Tetrahymena thermophild or Euplotes octocarinatus fused to eRF1 domains 2 and 3 from Saccharomyces cerevisiae. We found that the Tetrahymena hybrid eRF1 efficiently terminated at all three stop codons when expressed in yeast cells, indicating that domain 1 is not the sole determinant of stop codon recognition in Tetrahymena species. In contrast, the Euplotes hybrid facilitated efficient translation termination at UAA and UAG codons but not at the UGA codon. Together, these results indicate that while domain 1 facilitates stop codon recognition, other factors can influence this process. Our findings also indicate that these two ciliate species used distinct approaches to diverge from the universal genetic code.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available