Insertion, excision, and inversion of Tn5.
Insertion, excision, and inversion of Tn5.
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DOI：
10.1101/sqb.1981.045.01.020
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
D. Berg;C. Egner;B. Hirschel;J. Howard;L. Johnsrud;R. Jorgensen;T. Tlsty
中科院分区：
文献类型：
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作者：
D. Berg;C. Egner;B. Hirschel;J. Howard;L. Johnsrud;R. Jorgensen;T. Tlsty
细菌转座子的决定性特征是，在没有广泛的DNA序列同源性或recA蛋白的情况下，它们能够移动到新的位置(有关综述，请参阅Calos和Miller 1980；Starlinger 1980)。转座子通过促进不同物种之间的基因流动以及改变单一物种内基因的排列和表达控制来增加细菌种群的适合度。含有抗生素耐药性基因的转座子似乎是导致相同的耐药性基因在其他无关的R因子质粒中重复出现的原因(见Falkow 1975)。在实验室中，这种抗性转座子可以用来突变寄主基因，探测和改变基因表达的调控，并将基因转移到新的位置。本文重点研究了Tn5的性质，它是一个5700 bp的转座子，包含一个编码卡那霉素抗性(Kan)的基因，其末端是1500-BP的反向重复序列(Berg等人)。1975年；伯格1977年)。Tn5是从克雷伯氏菌中获得的R因子质粒的天然成分，与通常存在于大肠杆菌K12染色体上的序列没有同源性(Berg和Drummond，1978)。Tn5插入到基因组中许多不同的位置。它导致操纵子远端基因表达的极性突变，并可以通过切除recA§和recA-细胞中的TN5而逆转(Berg 1977；Shaw和Berg 1979；Berg等人)。1980)。Tn5基因的删除与其向新位点的转移无关。相反，转位会在原始位置留下一份Tn5的副本(Berg 1977)。因此，移位和切除是两个截然不同的过程的结果。限制性内切酶(Jorgensen等人和DNA序列(E.-A.Auerswald和H.Schaller，Pers.通信。)分析表明，Tn5的左右反向重复序列几乎完全相同。然而，对Tn5插入和取代衍生物的分析表明，右侧的反向重复序列编码Tn5转座到新位点(转座酶)所必需的反式作用功能，而左侧的反向重复序列不编码转座酶，但包含负责转座子中央部分Kan r基因表达的启动子(Meyer等人)。1979年；Rothstein等人。1980)。
The defining characteristic of bacterial transposons is their ability to move to new loci in the absence of extensive DNA sequence homology or the recA protein (for review, see Calos and Miller 1980; Starlinger 1980). Transposons increase the fitness of bacterial populations by facilitating gene flow among different species and by changing the arrangement and the control of expression of genes within a single species. Transposons that contain genes for antibiotic resistance appear to be responsible for the recurrence of the same resistance genes in otherwise unrelated R-factor plasmids (see Falkow 1975). In the laboratory, such resistance transposons can be used to mutate host genes, to probe and alter the control of gene expression, and to move genes to new locations.In this paper we focus on the properties of Tn5, a 5700-bp transposon that contains a gene encoding kanamycin resistance (kan) bracketed by terminal 1500-bp inverted repeats (Berg et al. 1975; Berg 1977). Tn5 is a natural component of an R-factor plasmid obtained from Klebsiella and has no homology with sequences normally present in the chromosome of Escherichia coli K12 (Berg and Drummond 1978). Tn5 inserts into many different sites in a genome. It causes mutations that are polar on the expression of distal genes in the operon and can revert by excision of Tn5 in both recA § and recA-cells (Berg 1977; Shaw and Berg 1979; Berg et al. 1980). The excision of Tn5 is not correlated with its n~ vement to new sites. Conversely, transposition leaves one copy of Tn5 at the original site (Berg 1977). Thus, transposition and excision result from two distinct processes. Restriction endonuclease (Jorgensen et al. 1979a) and DNA sequence (E.-A. Auerswald and H. Schaller, pers. comm.) analyses have shown that the left and right inverted repeats of Tn5 are nearly identical. However, analyses of insertion and substitution derivatives of Tn5 have shown that the right inverted repeat encodes a trans-acting function necessary for transposition of Tn5 to new sites (a transposase) and that the left inverted repeat does not encode a transposase but contains the promoter responsible for the expression of the kan r gene in the central portion of the transposon (Meyer et al. 1979; Rothstein et al. 1980).