Physical analysis of deletion mutations in the ilvGEDA operon of Escherichia coli K-12.
Physical analysis of deletion mutations in the ilvGEDA operon of Escherichia coli K-12.
复制标题
大肠杆菌 K-12 ilvGEDA 操纵子缺失突变的物理分析。
DOI：
10.1128/jb.162.2.598-606.1985
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发表时间：
1985
影响因子：
3.2
通讯作者：
Lawther,RP
中科院分区：
文献类型：
--
作者：
Driver,RP;Lawther,RP
使用大肠杆菌K-12 ilvGEDA操纵子的克隆片段与基因组印迹的DNA-DNA杂交来确定ilvGEDA操纵子的一系列缺失突变的物理尺寸。最小的突变是由ilvD内约200个碱基对的缺失引起的，而最大的突变是由包括rep基因在内的17个内切酶的缺失引起的。这些突变体中的三个的结构表明，缺失的形成是由保留在染色体中的Tn 5（或Tn 5 -131）介导的。这是首次观察到这种类型的Tn 5介导的事件。我们对含有ilvG缺失的菌株的总乙酰羟酸合酶活性的分析表明，野生型E. coli K-12缺乏酶活性。ilvD的小的200个碱基对缺失证实了在ilvA的5'端存在强极性位点。这些缺失的详细结构应该证明是有用的，在这一地区的其他基因的调查。该基因组分析表明，先前通过分析重组噬菌体和质粒建立的ilv限制性位点图谱与基因组上的一致。
DNA-DNA hybridization of cloned segments of the Escherichia coli K-12 ilvGEDA operon to genomic blots was used to determine the physical dimensions of a series of deletion mutations of the ilvGEDA operon. The smallest mutation resulted from the deletion of approximately 200 base pairs from within ilvD, whereas the largest mutation resulted from the deletion of 17 kilobases including the rep gene. The structure of three of these mutants indicates that formation of the deletions was mediated by Tn5 (or Tn5-131) that is retained in the chromosome. This is the first observation of this type of Tn5-mediated event. Our analysis of the total acetohydroxy acid synthase activity of strains containing deletions of ilvG indicates that the truncated ilvG polypeptide of wild-type E. coli K-12 lacks enzyme activity. The small 200-base-pair deletion of ilvD confirms the presence of a strong polar site 5' to ilvA. The detailed structure of these deletions should prove useful for the investigation of other genes in this region. This genomic analysis demonstrates that the ilv restriction site map that was established previously by the analysis of recombinant bacteriophage and plasmids is identical to that on the genome.