酵母线粒体DNA上var1基因的定位与结构：40.0等位基因的核苷酸序列

Location and structure of the var1 gene on yeast mitochondrial DNA: nucleotide sequence of the 40.0 allele.

作者信息

Hudspeth M E, Ainley W M, Shumard D S, Butow R A, Grossman L I

出版信息

Cell. 1982 Sep;30(2):617-26. doi: 10.1016/0092-8674(82)90258-6.

DOI:10.1016/0092-8674(82)90258-6

Abstract

Alleles of the var1 locus on yeast mitochondrial DNA specify the size of var1 ribosomal protein. We report the nucleotide sequence of a var1 allele that determines the smallest var1 protein. It contains an open reading frame of 396 codons, which we identify as the structural gene for var1 protein. The var1 protein specified by this allele has an amino acid composition in close agreement with that predicted by the DNA sequence. The var1 coding region is highly unusual: it is 89.6% AT and contains a 46 bp GC-rich palindromic cluster that accounts for 38% of the total GC residues. Our results strongly suggest that like mammalian mitochondria but unlike those from Neurospora, yeast mitochondria use AUA as a methionine codon. Comparison with the sequence of a var1 allele specifying a larger protein suggests that some size polymorphism of var1 protein results from in-frame insertions of a variable number of AAT (Asn) codons.

摘要

酵母线粒体DNA上var1位点的等位基因决定了var1核糖体蛋白的大小。我们报告了一个决定最小var1蛋白的var1等位基因的核苷酸序列。它包含一个396个密码子的开放阅读框，我们将其鉴定为var1蛋白的结构基因。由该等位基因指定的var1蛋白的氨基酸组成与DNA序列预测的结果非常一致。var1编码区非常独特：它的AT含量为89.6%，并包含一个46bp富含GC的回文簇，占总GC残基的38%。我们的结果强烈表明，与哺乳动物线粒体一样，但与粗糙脉孢菌的线粒体不同，酵母线粒体使用AUA作为甲硫氨酸密码子。与指定较大蛋白的var1等位基因序列进行比较表明，var1蛋白的一些大小多态性是由可变数量的AAT（Asn）密码子的框内插入导致的。