Stop codon recognition in ciliates:: Euplotes release factor does not respond to reassigned UGA codon
Stop codon recognition in ciliates:: Euplotes release factor does not respond to reassigned UGA codon
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DOI：
10.1093/embo-reports/kve156
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发表时间：
2001-08-01
期刊：
影响因子：
7.7
通讯作者：
Jean-Jean, O
中科院分区：
文献类型：
--
作者：
Kervestin, S;Frolova, L;Jean-Jean, O
在真核生物中，多肽释放因子1（eRF 1）参与翻译终止在所有三个终止密码子。然而，终止密码子的解码机制仍然未知。已经假设eRF1与终止密码子的直接相互作用。最近的研究集中在纤毛虫的eRF1，其中一些终止密码子被重新分配给有义密码子。使用基于哺乳动物核糖体的体外测定，我们表明，eRF1从纤毛虫的Euplotes aediculatus响应UAA和UAG作为终止密码子，并缺乏破译UGA密码子的能力，该密码子编码半胱氨酸在这种生物体。这一结果有力地表明，在纤毛虫变异遗传密码eRF1不承认重新分配的密码子。最近的假说描述终止密码子歧视eRF1是不完全一致的一套eRF1序列，目前为止，需要直接的实验测试。
In eukaryotes, the polypeptide release factor 1 (eRF1) is involved in translation termination at all three stop codons. However, the mechanism for decoding stop codons remains unknown. A direct interaction of eRF1 with the stop codons has been postulated. Recent studies focus on eRF1 from ciliates in which some stop codons are reassigned to sense codons. Using an in vitro assay based on mammalian ribosomes, we show that eRF1 from the ciliate Euplotes aediculatus responds to UAA and UAG as stop codons and lacks the capacity to decipher the UGA codon, which encodes cysteine in this organism. This result strongly suggests that in ciliates with variant genetic codes eRF1 does not recognize the reassigned codons. Recent hypotheses describing stop codon discrimination by eRF1 are not fully consistent with the set of eRF1 sequences available so far and require direct experimental testing.