THE CODON CUG IS READ AS SERINE IN AN ASPOROGENIC YEAST CANDIDA-CYLINDRACEA
THE CODON CUG IS READ AS SERINE IN AN ASPOROGENIC YEAST CANDIDA-CYLINDRACEA
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DOI：
10.1038/341164a0
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发表时间：
1989-09-14
期刊：
影响因子：
64.8
通讯作者：
IWASAKI, S
中科院分区：
文献类型：
--
作者：
KAWAGUCHI, Y;HONDA, H;IWASAKI, S
已经报道了几种微生物与通用遗传密码的偏差。终止密码子用于编码草履虫1、2、支原体3、支原体4、4、5和大肠杆菌中的一些氨基酸，UGA终止密码子用于编码硒代半胱氨酸6。在线粒体中，意义密码子向终止密码子或编码其他氨基酸的密码子的变化也有报道7,8。在这里，我们报告了另一个与通用密码子不同的例子，这次是在一种不形成孢子的酵母——圆柱假丝酵母中，其中亮氨酸的通用密码子CUG被用来编码丝氨酸。这一结论是基于以下观察得出的：(1)酵母胞外脂肪酶的氨基酸组成和部分氨基酸序列与从互补DNA推断的结果一致（假设CUG指定丝氨酸）；(2)丝氨酸，而不是亮氨酸，在合成的CUG低聚物存在的情况下，在无细胞翻译系统中从该酵母中加入到多肽中。
DEVIATIONS from the universal genetic code have been reported for several microorganisms. Termination codons are used for cod-ing some amino acids inParamecium1,2,Mycoplasma3orTetrahymena4,5, and inEscherichia coli, the UGA termination codon is used to code for selenocysteine6. In mitochondria, the changes of sense codons to termination codons or to codons encoding other amino acids have also been reported7,8. Here we report another example of divergence from the universal code, this time in a non-spore-forming yeastCandida cylindracea, in which the uni-versal codon for leucine, CUG, is used to code for serine. This conclusion is based on the observations that: (1) the amino-acid composition and the partial amino-acid sequences of an extracel-lular lipase from this yeast agreed with those deduced from the complementary DNA if CUG was assumed to specify serine; and (2) serine, but not leucine, was incorporated into a polypeptide in a cell-free translation system from this yeast in the presence of a synthetic CUG oligomer.