IS2, a genetic element for turn-off and turn-on of gene activity in E. coli

Saedler, Heinz; Reif, H. J.; Hu, Sylvia; Davidson, Norman

doi:10.1007/bf00268569

Cited by 182 publications

(72 citation statements)

References 28 publications

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“…It has heen postulated that IS2 carries a strong promoter in orientation II (22). However, our data are not compatible with this hypothesis: Although in all three strains derived from mutant galOP-308 ( fig.…”

Section: Resultscontrasting

confidence: 94%

Deletions and DNA rearrangements within the transposable DNA element IS2. A model for the creation of palindromic DNA by DNA repair synthesis

1980

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Three derivatives of mutant qalOP-308::IS2-I of Escherichia coli were characterized by DNA sequence anaTyis. Deletions and DNA sequence rearrangements were observed which apparently were initiated at short A-T rich inverted repeats within IS2. Two of the mutants carried newly synthesized DNA sequences which were inverted copies of already existing IS2 sequences. Thus long stretches with twofold symmetry were formed. It is discussed whether these inverted repeats were formed by DNA repair synthesis which was initiated at the A-T rich palindromes of IS2.

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Section: Resultscontrasting

confidence: 94%

Deletions and DNA rearrangements within the transposable DNA element IS2. A model for the creation of palindromic DNA by DNA repair synthesis

1980

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“…Some of these elements have also been shown to activate nearby genes by means of outwardly directed promoter sequences (1,5,16,29,42). A similar role has been observed with IS4351.…”

Section: Discussionmentioning

confidence: 55%

Complete nucleotide sequence of insertion element IS4351 from Bacteroides fragilis

Rasmussen¹,

Odelson²,

Macrina³

1987

J Bacteriol

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The nucleotide sequence and genetic analyses of one of the directly repeated sequences flanking the macrolide-lincosamide-streptogramin B drug resistance determinant, ermF, from the Bacteroides fragilis R plasmid, pBF4, suggested that this region is an insertion sequence (IS) (3,9,14,17,18,40).Within the obligately anaerobic Bacteroides spp., three independently isolated R plasmids, pBF4 (44), pBFTM1O (41), and pBI136 (36), have been described which confer resistance to macrolide, lincosamide, and streptogramin B (MLS)-type antibiotics. In each of these plasmids, the MLS resistance genes are flanked by directly repeated (DR) DNA sequences of approximately 1.1 kb (12,31,35). The MLS resistance determinant and the flanking DR sequences on pBF4 (33, 34) and pBFTM10 (28) have been demonstrated to undergo transposition in both Escherichia coli and Bacteroides spp. and have been designated transposons Tn4351 and Tn4400, respectively. A similar observation has been noted with the analogous region of pBI136 (C. J. Smith, submitted for publication).During the course of studying the genetic basis of MLS resistance in the Bacteroides fragilis plasmid pBF4, we determined that this resistance gene, ermF, is transcriptionally dependent on an adjacent DR sequence (27). In the present study, we report the nucleotide sequence of one member of the DR segments of pBF4. Computer analyses of this nucleotide sequence revealed structural similarities of this element to procaryotic IS elements, although no significant homology was seen at the nucleotide level. We also examined the biological activity of this element in E. coli and present evidence that it can undergo recA-independent transposition. We propose to designate this element IS4351. MATERIALS AND METHODSBacterial strains, plasmids, and culture conditions. Bacterial strains and plasmids are shown in Table 1. B. fragilis V479-1 or V598, V600, and V689 were maintained on supplemented brain heart infusion broth (22) containing 5 ,ug of clindamycin per ml or 10 jig of tetracycline per ml as appropriate. E. coli JM101 was maintained on YT medium (23). Other E. coli strains were maintained on LB medium (23) with antibiotics as follows: V831, 10 ,ug of tetracycline per ml; V1317, 50 jig of ampicillin per ml; V1337, 300 ,ug of erythromycin per ml; and V1348, 50 ,ug of ampicillin per ml, 50 jig of chloramphenicol per ml, and 10 jig of tetracycline per ml.Genetic transformation of E. coli. E. coli strains JM101 and HB101 were transformed with bacteriophage and plasmid DNA, respectively, as previously described (27). Plasmid DNA and M13

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“…Shortly after, it was established that IS were normal residents of the Escherichia coli chromosome (4) sometimes present in multiple copies. They were shown to be involved in generating deletions (5) and in activating gene expression (6). They were also identified as constituents of bacterial plasmids (7).…”

Section: Historymentioning

confidence: 99%

Everyman's Guide to Bacterial Insertion Sequences

et al. 2015

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The number and diversity of known prokaryotic insertion sequences (IS) have increased enormously since their discovery in the late 1960s. At present the sequences of more than 4000 different IS have been deposited in the specialized ISfinder database. Over time it has become increasingly apparent that they are important actors in the evolution of their host genomes and are involved in sequestering, transmitting, mutating and activating genes, and in the rearrangement of both plasmids and chromosomes. This review presents an overview of our current understanding of these transposable elements (TE), their organization and their transposition mechanism as well as their distribution and genomic impact. In spite of their diversity, they share only a very limited number of transposition mechanisms which we outline here. Prokaryotic IS are but one example of a variety of diverse TE which are being revealed due to the advent of extensive genome sequencing projects. A major conclusion from sequence comparisons of various TE is that frontiers between the different types are becoming less clear. We detail these receding frontiers between different IS-related TE. Several, more specialized chapters in this volume include additional detailed information concerning a number of these.In a second section of the review, we provide a detailed description of the expanding variety of IS, which we have divided into families for convenience. Our perception of these families continues to evolve and families emerge regularly as more IS are identified. This section is designed as an aid and a source of information for consultation by interested specialist readers.

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IS2, a genetic element for turn-off and turn-on of gene activity in E. coli

Cited by 182 publications

References 28 publications

Deletions and DNA rearrangements within the transposable DNA element IS2. A model for the creation of palindromic DNA by DNA repair synthesis

Deletions and DNA rearrangements within the transposable DNA element IS2. A model for the creation of palindromic DNA by DNA repair synthesis

Complete nucleotide sequence of insertion element IS4351 from Bacteroides fragilis

Everyman's Guide to Bacterial Insertion Sequences

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