Eukaryotic Release Factor 3 Is Required for Multiple Turnovers of Peptide Release Catalysis by Eukaryotic Release Factor 1
Eukaryotic Release Factor 3 Is Required for Multiple Turnovers of Peptide Release Catalysis by Eukaryotic Release Factor 1
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DOI：
10.1074/jbc.m113.487090
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发表时间：
2013-10-11
影响因子：
4.8
通讯作者：
Green, Rachel
中科院分区：
文献类型：
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作者：
Eyler, Daniel E.;Wehner, Karen A.;Green, Rachel
真核肽释放因子3（eRF3）是真核生物中一个保守的、参与翻译终止的必需基因。我们已经系统地测量了eRF3的贡献与饱和和限制水平的真核释放因子1（eRF1）的肽释放速率。虽然eRF 3适度刺激肽释放的绝对速率（类似于5倍），但当eRF 1是限制性的（>20倍）时，它强烈增加肽释放的速率。这种效应在所有终止密码子和各种背景下都是可推广的。进一步的研究表明，eRF1在肽释放和亚基解离后仍然与核糖体复合物结合，并且eRF3促进eRF1从这些终止后复合物中解离。这些数据与模型一致，其中eRF3主要影响eRF1和核糖体之间的结合相互作用，无论是在肽释放之前还是之后。eRF3作为护送eRF1进入其完全适应状态的角色很容易与其与翻译的GT3 EFTu的密切序列相似性相协调。
Eukaryotic peptide release factor 3 (eRF3) is a conserved, essential gene in eukaryotes implicated in translation termination. We have systematically measured the contribution of eRF3 to the rates of peptide release with both saturating and limiting levels of eukaryotic release factor 1 (eRF1). Although eRF3 modestly stimulates the absolute rate of peptide release (similar to 5-fold), it strongly increases the rate of peptide release when eRF1 is limiting (>20-fold). This effect was generalizable across all stop codons and in a variety of contexts. Further investigation revealed that eRF1 remains associated with ribosomal complexes after peptide release and subunit dissociation and that eRF3 promotes the dissociation of eRF1 from these post-termination complexes. These data are consistent with models where eRF3 principally affects binding interactions between eRF1 and the ribosome, either prior to or subsequent to peptide release. A role for eRF3 as an escort for eRF1 into its fully accommodated state is easily reconciled with its close sequence similarity to the translational GTPase EFTu.