EFFECTS OF SURROUNDING SEQUENCE ON THE SUPPRESSION OF NONSENSE CODONS
EFFECTS OF SURROUNDING SEQUENCE ON THE SUPPRESSION OF NONSENSE CODONS
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DOI：
10.1016/0022-2836(83)90087-6
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发表时间：
1983-01-01
影响因子：
5.6
通讯作者：
ALBERTINI, AM
中科院分区：
文献类型：
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作者：
MILLER, JH;ALBERTINI, AM
利用lacI-Z融合系统，测定大肠杆菌I基因中无义密码子的抑制效率。牛乳糖活动。研究了4个琥珀色抑制子作用于I基因已知位置上42个不同琥珀色密码子的效率，以及1个琥珀色抑制子作用于14个不同琥珀色密码子的效率。琥珀色抑制子supE （Su2）的效果最大，其效率变化幅度超过35倍，而UGA抑制子的效率变化幅度为170倍。某些UGA位点被UGA抑制子抑制得很差（< 0.2%），因此它们最初未被检测为无义突变。抑制效率与密码子被抑制的3”侧的序列有关，在许多情况下与3”侧的第一个碱基有关。A或G后面的密码子抑制良好，U或C后面的密码子抑制较差。也有例外，因为后跟CUG或CUC的密码子被很好地抑制了。考虑了周围序列对抑制效率影响的模型。
Using a lacI-Z fusion system, one determined the efficiency of suppression of nonsense codons in the I gene of Escherichia coli by assaying .beta.-galactosidase activity. The efficiency of 4 amber suppressors acting on 42 different amber (UAG) codons at known positions in the I gene and the efficiency of a UAG suppressor at 14 different UGA codons were examined. The largest effects were found with the amber suppressor supE (Su2), which displayed efficiencies that varied over a 35-fold range, and with the UGA suppressor, which displayed a 170-fold variation in efficiency. Certain UGA sites were so poorly suppressed (< 0.2%) by the UGA suppressor that they were not originally detected as nonsense mutations. Suppression efficiency can be correlated with the sequence on the 3'' side of the codon being suppressed and in many cases with the first base on the 3'' side. Codons followed by A or G are well suppressed and codons followed by U or C are poorly suppressed. There are exceptions, since codons followed by CUG or CUC are well suppressed. Models explaining the effect of the surrounding sequence on suppression efficiency are considered.