PHYLOGENETIC DISTRIBUTION OF BRANCHED RNA-LINKED MULTICOPY SINGLE-STRANDED-DNA AMONG NATURAL ISOLATES OF ESCHERICHIA-COLI
PHYLOGENETIC DISTRIBUTION OF BRANCHED RNA-LINKED MULTICOPY SINGLE-STRANDED-DNA AMONG NATURAL ISOLATES OF ESCHERICHIA-COLI
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DOI：
10.1128/jb.172.11.6175-6181.1990
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发表时间：
1990-11-01
影响因子：
3.2
通讯作者：
WHITTAM, TS
中科院分区：
文献类型：
--
作者：
HERZER, PJ;INOUYE, S;WHITTAM, TS
多拷贝单链DNA （msDNA）是一种支链DNA- rna分子，在大肠杆菌B和临床菌株Cl-1中已被证明是由逆转录酶合成的。我们报告说，ECOR收集的菌株中，有13%的菌株产生msDNA，这是72个大肠杆菌分离株的样本，代表了该物种遗传变异的广度。四个主要亚特异性群体中的三个包括msdna产生菌株。筛选25株与产生msdna的临床菌株有遗传关系的分离株，发现了22株产生msdna的菌株。基于20个酶编码位点等位基因变异的系统发育树电泳检测显示，两个主要集群和几个由合成msDNA的菌株组成的深分支。虽然大肠杆菌K-12不含msDNA，但其他与K-12家族密切相关的菌株却含有msDNA。结果支持了msdna合成系统的假设，包括逆转录酶基因，是最近在不同的大肠杆菌谱系中独立获得的。
Multicopy single-stranded DNA (msDNA), a branched DNA-RNA molecule, has been shown in Escherichia coli B and clinical strain Cl-1 to be synthesized by reverse transcriptase. We report that 13% of the strains of the ECOR collection, a sample of 72 E. coli isolates representing the breadth of genetic variation of the species, produce msDNA. Three of the four major subspecific groups include msDNA-producing strains. Screening of 25 isolates that are genetically related to msDNA-producing clinical strains uncovered 22 additional msDNA-producing strains. A phylogenetic tree based on allelic variation detected electrophoretically at 20 enzyme-encoding loci revealed two major clusters and several deep branches composed of strains that synthesize msDNA. Although E. coli K-12 does not harbor msDNA, other closely related strains of the K-12 family do. The results support the hypothesis that msDNA-synthesizing systems, including reverse transcriptase genes, were acquired recently and independently in different lineages of E. coli.