IS103, a new insertion element in Escherichia coli: characterization and distribution in natural populations.
IS103, a new insertion element in Escherichia coli: characterization and distribution in natural populations.
复制标题
IS103，大肠杆菌中的新插入元件：自然群体中的特征和分布。
DOI：
10.1093/genetics/121.3.423
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发表时间：
1989
期刊：
影响因子：
3.3
通讯作者：
Hartl,DL
中科院分区：
文献类型：
--
作者：
Hall,BG;Parker,LL;Betts,PW;DuBose,RF;Sawyer,SA;Hartl,DL
IS 103是在大肠杆菌K12中发现的先前未知的插入序列。我们对IS 103进行了测序，发现它是一个1441-bp的元件，由一个1395-bp的核心组成，两侧是不完全的23-bp反向重复序列。IS 103导致其插入的靶序列的6-bp重复。在野生型E. coli K12菌株HfrC.在菌株X342及其后代中，有两个额外的拷贝，其中一个位于bglF基因内。IS 103能够从bglF内切除并恢复该基因的功能。IS 103与IS 3具有44%的序列同一性，表明这两个插入序列可能来自共同的祖先。我们检测了IS 103在ECOR自然分离株染色体和质粒中的分布。杆菌IS 103被发现在36的71个菌株检查，它强烈倾向于栖息在质粒，而不是染色体。观察到的IS 103的分布预测的9种不同的模式，根据拷贝数和拷贝数对健身的影响，换位的监管分布的比较表明，IS 103的换位是强烈的监管，它只有轻微的影响健身。IS 103在E.尽管质粒上存在质粒，但其在大肠杆菌群体中的表达表明质粒倾向于保留在密切相关的菌株内，并且向远缘菌株的转移被抑制。
IS103 is a previously unknown insertion sequence found in Escherichia coli K12. We have sequenced IS103 and find that it is a 1441-bp element that consists of a 1395-bp core flanked by imperfect 23-bp inverted repeats. IS103 causes a 6-bp duplication of the target sequence into which it inserts. There is a single copy of IS103 present in wild-type E. coli K12 strain HfrC. In strain X342 and its descendents there are two additional copies, one of which is located within the bglF gene. IS103 is capable of excising from within bglF and restoring function of that gene. IS103 exhibits 44% sequence identity with IS3, suggesting that the two insertion sequences are probably derived from a common ancestor. We have examined the distribution of IS103 in the chromosomes and plasmids of the ECOR collection of natural isolates of E. coli. IS103 is found in 36 of the 71 strains examined, and it strongly tends to inhabit plasmids rather than chromosomes. Comparison of the observed distribution of IS103 with distributions predicted by nine different models for the regulation of transposition according to copy number and of the effects of copy number on fitness suggest that transposition of IS103 is strongly regulated and that it has only minor effects on fitness. The strong clustering of IS103 within one phylogenetic subgroup of the E. coli population despite its presence on plasmids suggests that plasmids tend to remain within closely related strains and that transfer to distantly related strains is inhibited.