Mutations in elongation factor EF-1 alpha affect the frequency of frameshifting and amino acid misincorporation in Saccharomyces cerevisiae.
Mutations in elongation factor EF-1 alpha affect the frequency of frameshifting and amino acid misincorporation in Saccharomyces cerevisiae.
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DOI：
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发表时间：
1988-12
期刊：
影响因子：
3.3
通讯作者：
M. Sandbaken;M. Culbertson
中科院分区：
文献类型：
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作者：
M. Sandbaken;M. Culbertson
对真核延伸因子EF-1 α的突变分析表明，该蛋白在遗传密码翻译过程中起着限制错误频率的作用。我们发现氨基酸错误结合和阅读框错误都是由EF-1控制的。为了研究该蛋白的功能，我们在体外用羟胺诱变了酿酒酵母中编码EF-1 α的TEF2基因。16个独立的TEF2等位基因通过抑制移码突变的能力被分离出来。DNA序列分析确定了EF-1 α蛋白中8个不同的位点，这些位点在突变时提高了误翻译的频率。这些位点位于蛋白质的两个不同区域。位于蛋白质的gtp结合和水解结构域中或附近的氨基酸取代导致移码和无义突变的抑制。这些突变可能通过改变GTP的结合或水解来影响误翻译。位于假定的氨基酰基- trna结合区附近的氨基酸替换也抑制移码和无义突变。这些突变可能改变EF-1 α与氨基酰基trna的结合。EF-1 α移码和无义抑制突变的鉴定表明该蛋白在限制氨基酸错误结合和读框错误中起作用。我们认为这些类型的错误是由一个共同的机制或密切相关的机制控制的。
A mutational analysis of the eukaryotic elongation factor EF-1 alpha indicates that this protein functions to limit the frequency of errors during genetic code translation. We found that both amino acid misincorporation and reading frame errors are controlled by EF-1 alpha. In order to examine the function of this protein, the TEF2 gene, which encodes EF-1 alpha in Saccharomyces cerevisiae, was mutagenized in vitro with hydroxylamine. Sixteen independent TEF2 alleles were isolated by their ability to suppress frameshift mutations. DNA sequence analysis identified eight different sites in the EF-1 alpha protein that elevate the frequency of mistranslation when mutated. These sites are located in two different regions of the protein. Amino acid substitutions located in or near the GTP-binding and hydrolysis domain of the protein cause suppression of frameshift and nonsense mutations. These mutations may effect mistranslation by altering the binding or hydrolysis of GTP. Amino acid substitutions located adjacent to a putative aminoacyl-tRNA binding region also suppress frameshift and nonsense mutations. These mutations may alter the binding of aminoacyl-tRNA by EF-1 alpha. The identification of frameshift and nonsense suppressor mutations in EF-1 alpha indicates a role for this protein in limiting amino acid misincorporation and reading frame errors. We suggest that these types of errors are controlled by a common mechanism or closely related mechanisms.