An evolutionary analysis of iso-is1 elements from Escherichia coli and Shigella strains.

Ohtsubo, Eiichi; Ohtsubo, Hideomi; Doroszkiewicz, W.; Nyman, Kate; Allen, D. C.; Davison, Daniel B.

doi:10.2323/jgam.30.359

Cited by 22 publications

(23 citation statements)

References 22 publications

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“…Seventy-nine base pairs of the B' reading frame overlap the 3' end of the insA coding frame. The B' frame does not seem to encode a polypeptide, since several iso-ISI elements have no initiation codons in the overlapping region (7,12). The following facts, however, cannot be readily accounted for in the expression of insA and insB in ISIR, particularly the expression of insB and its extended region: (i) A ribosome-binding sequence does not precede insB but does precede insA.…”

mentioning

confidence: 99%

“…ISI is present in various copy numbers in chromosomes as well as plasmids of certain bacteria belonging to the family Enterobacteriaceae (6)(7)(8)(9). ISl from plasmid R100 is 768 base pairs (bp) long (10); IS] elements from the other sources have divergent sequences (7,11,12) and hence are collectively termed iso-IS) elements (7). IS] in R100 (termed ISIR) comprises two reading frames, insA and insB, that are essential for transposition and cointegration (13)(14)(15).…”

mentioning

confidence: 99%

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Frameshifting is required for production of the transposase encoded by insertion sequence 1.

Sekine

Ohtsubo

1989

Proc. Natl. Acad. Sci. U.S.A.

122

113

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Insertion sequence IS] has two coding frames, insA and insB, which are essential for its transposition. Here, we show that a frameshifting event in the -1 direction from the 3' end region of the insA frame to an open reading frame (B' frame), extending from the 5' end of the insB frame, is involved in production of the InsA-B'-InsB fusion protein that has IS) transposase activity. The frameshifting event is likely to have occurred at the sequence AAAAAC where the insA frame overlaps the B' frame. Interestingly, this sequence is also present in one of the two sequences identified in retroviruses as frameshift signals for production of transframe polyproteins from the overlapping genes gag-pro or gag-propol.

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mentioning

confidence: 99%

mentioning

confidence: 99%

Frameshifting is required for production of the transposase encoded by insertion sequence 1.

Sekine

Ohtsubo

1989

Proc. Natl. Acad. Sci. U.S.A.

122

113

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“…On the basis of mutations generated upon insertion of IS elements, the frequency of transposition has been estimated to range from 10-3 to 10-7 per element per generation in Escherichia coli grown under laboratory conditions. In these experiments, transposition rates varied with the class of IS element, host genotype, target sequence, and physiological conditions (1,4,9,27).Most information on IS distribution and abundance stems from analysis of enteric bacteria, particularly E. coli (16,21,24,29). Natural strains of E. coli recovered from diverse sources are highly variable in both the numbers and genomic locations of several classes of IS (22,29), suggesting that elements transpose regularly within a host.…”

mentioning

confidence: 99%

“…Most information on IS distribution and abundance stems from analysis of enteric bacteria, particularly E. coli (16,21,24,29). Natural strains of E. coli recovered from diverse sources are highly variable in both the numbers and genomic locations of several classes of IS (22,29), suggesting that elements transpose regularly within a host.…”

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confidence: 99%

The ancestry of insertion sequences common to Escherichia coli and Salmonella typhimurium

Bisercić

Ochman

1993

J Bacteriol

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Despite very restricted gene exchange between Escherichia coli and Salmonella typhimurium, both species harbor several of the same classes of insertion sequences. To determine whether the present-day distribution of these transposable elements is due to common ancestry or to horizontal transfer, we determined the sequences of IS] and IS200 from natural isolates of S. typhimurium and E. coli. One strain of S. typhimurium harbored an IS) element identical to that originally recovered from E. coli, suggesting that the element was recently transferred between these two species. The level of sequence divergence between copies of IS200 from E. coli and S. typhimurium ranged from 9.5 to 10.7%, indicating that IS200, unlike IS], has not been repeatedly transferred between these enteric species since E. coli and S. typhimurium diverged from a common ancestor. Levels of variability in IS] and IS200 for strains of E. coli and S. typhimurium show that each class of insertion sequence has a characteristic pattern of transposition within and among host genomes.The genomes of most bacteria contain many distinct classes of insertion sequences (IS; e.g., IS], IS2, and IS3). These elements are small translocating segments of DNA that occur on the host chromosome and on plasmids and have the potential to move both within and among bacterial genomes. The ability of IS to mediate gene transfer and affect gene activity has led to speculation about their role in bacterial evolution (5), but until recently, the rate and extent of transposition of IS elements among natural isolates have remained unknown. On the basis of mutations generated upon insertion of IS elements, the frequency of transposition has been estimated to range from 10-3 to 10-7 per element per generation in Escherichia coli grown under laboratory conditions. In these experiments, transposition rates varied with the class of IS element, host genotype, target sequence, and physiological conditions (1,4,9,27).Most information on IS distribution and abundance stems from analysis of enteric bacteria, particularly E. coli (16,21,24,29). Natural strains of E. coli recovered from diverse sources are highly variable in both the numbers and genomic locations of several classes of IS (22,29), suggesting that elements transpose regularly within a host. By using pairs of identical isolates stored separately in stab cultures for over 50 years, Green et al. (10)

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“…1, 1-3 for coding strand and 4-7 for complementary strand) that together encode Bombyx EH were synthesized by the solid-phase phosphoamidite method on an Applied Biosystems model 380B DNA synthesizer. In designing these nucleotides the codon usage in E. coli [8] was taken into account. After purification, nucleotides were mixed, annealed and ligated into pUC18 with T4 DNA ligase.…”

Section: Synthesis Of the Ell Gene And Construction Of Secretion Vectmentioning

confidence: 99%

Eclosion hormone of the silkworm Bombyx mori Expression in Escherichia coli and location of disulfide bonds

Kono¹,

Nagasawa²,

Kataoka³

et al. 1990

FEBS Letters

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A gene encoding eclosion hormone (EH) from the silkworm, Bombyx mori was chemically synthesized, inserted into a secretion vector and expressed in Escherichia coli, leading to the production of biologically active EH. Sequence analysis of cystine-containing peptides in a thermolysin digest of this EH established the locations of 3 disulfide bonds in the molecule. Evidence was also obtained that the 6 residues at the NHz-terminal are dispensable but 4 residues at the COOH-terminal play an important role in EH activity.

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An evolutionary analysis of iso-is1 elements from Escherichia coli and Shigella strains.

Cited by 22 publications

References 22 publications

Frameshifting is required for production of the transposase encoded by insertion sequence 1.

Frameshifting is required for production of the transposase encoded by insertion sequence 1.

The ancestry of insertion sequences common to Escherichia coli and Salmonella typhimurium

Eclosion hormone of the silkworm Bombyx mori Expression in Escherichia coli and location of disulfide bonds

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