Molecular Characterization of an Aberrant Mercury Resistance Transposable Element from an Environmental Acinetobacter Strain

Kholodii, Gennady; Gorlenko, Zh. M.; Lomovskaya, Olga; Mindlin, S. Z.; Yurieva, Olga; Nikiforov, Vadim

doi:10.1006/plas.1993.1064

Cited by 33 publications

(30 citation statements)

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“…1 was found on a 60 kb conjugative plasmid (pKLH2) in an Acinetobacter calcoaceticus strain isolated from a mercury mine in Central Asia (Kholodii et al, 1993a). Southern hybridization analysis demonstrated that closely related mer operons are located in different plasmids of Acinetobacter strains isolated from mercury mines from different parts of the former Soviet Union (Mindlin et al, 1986) and in members of the family Enterobacteriaceae isolated from animals from the same locales and from soil samples collected in Chicago, USA (Z.…”

Section: Resultsmentioning

confidence: 99%

“…The first mer operon shown in Fig. 1 Kholodii et al (1993a) to explain the genesis of the mer element found in pKLH2 is shown at the top. R denotes the merR gene encoding the regulatory protein that ensures induction of the mer operon by Hg 2þ .…”

Section: Resultsmentioning

confidence: 99%

“…They are also invariably found in small numbers in pristine environments. In the present study, we surveyed a collection of environmental Gram-negative bacteria for the presence of the mer operons whose nucleotide sequences would be closely related to sequences of a mer operon from an Acinetobacter plasmid, pKLH2 (Kholodii et al, 1993a), or a mer operon from a Pseudomonas transposon, Tn5041 (G. Kholodii et al, submitted) that were first detected in a mercury mine in Central Asia. These two operons have the same gene organization as the mer operon of the well-known clinical mercury-resistance transposon Tn21.…”

Section: Introductionmentioning

confidence: 99%

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Intercontinental spread of promiscuous mercury‐resistance transposons in environmental bacteria

Yurieva

Kholodii

Minakhin

et al. 1997

Molecular Microbiology

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SummaryWe demonstrate that horizontal spread of mer operons similar to worldwide spread of antibiotic-resistance genes in medically important bacteria occurred in bacteria found in ores, soils and waters. The spread was mediated by different transposons and plasmids. Some of the spreading transposons were damaged in different ways but this did not prevent their further spread. Certain transposons are mosaics composed of segments belonging to distinct sequence types. These mosaics arose as a result of homologous and site-specific recombination. Our data suggest that the mercury-resistance operons of Gram-negative environmental bacteria can be considered as a worldwide population composed of a relatively small number of distinct recombining clones shared, at least partially, by environmental and clinical bacteria.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Intercontinental spread of promiscuous mercury‐resistance transposons in environmental bacteria

Yurieva

Kholodii

Minakhin

et al. 1997

Molecular Microbiology

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“…In most cases the adjacent gene encodes a member of the resolvase/invertase family (28). Furthermore, the transposon Tn5053, which has a tni module and outer ends closely related to those of class 1 integrons, has been shown to be preferentially inserted into the mrs region of plasmid RP1 (21). The mrs site is the binding site (res site) for a resolvase (ParA) encoded in the par region of RP1 (RP4) (11).…”

Section: Discussionmentioning

confidence: 99%

Transposons Tn 1696 and Tn 21 and Their Integrons In4 and In2 Have Independent Origins

Partridge

Brown

Stokes

et al. 2001

Antimicrob Agents Chemother

169

160

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The first 13.6 kb of the mercury and multidrug resistance transposon Tn1696, which includes the class 1 integron In4, has been sequenced. In4 is 8.33 kb long and contains the 5-conserved segment (5-CS) and 2.24 kb of the 3-conserved segment (3-CS) flanking four integrated cassettes. The 3-CS region is followed by one full copy and an adjacent partial copy of the insertion sequence IS6100 flanked, in inverse orientation, by two short segments (123 and 152 bp) from the outer right-hand end of class 1 integrons. This structure is representative of a distinct group of class 1 integrons that differs from In2, found in Tn21, and other related class 1 integrons. In4 does not include transposition genes but is bounded by characteristic 25-bp inverted repeats and flanked by a direct duplication of 5 bp of the target sequence, indicating that it was inserted by a transpositional mechanism. In4 lies between the resII and resI sites of a backbone mercury resistance transposon which is >99.5% identical to Tn5036. Although Tn21 and Tn1696 are both classified as members of the Tn21 subfamily of the Tn3 transposon family, the backbone mercury resistance transposons are only 79 to 96% identical. Tn21 also contains a region of about 0.7 kb not found in Tn1696. The integrons In2 and In4 carrying the antibiotic resistance genes have been inserted at different locations into distinct ancestral mercury resistance transposons. Thus, Tn21 and Tn1696 have independent histories and origins. Other transposons (Tn1403 and Tn1412) that include a class 1 integron also have independent origins. In all except Tn21, the integron is located within the res region of the backbone transposon.

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“…ORF2 proteins all have an ATP/GTP binding motif, similar to the motifs of the DnaA and DnaC proteins [32]. Other proteins of transposable elements showing the same type of motif are MuB of bacteriophage Mu [31,102,103] and TnsC of Tn7 [104], for which ATP binding has been demonstrated, TnpB of Tn552 [25,105], and TniB of Tn402 (= Tn5090) [106] and Tn5053 [107,108]. Like DnaC, these proteins are likely to form part of 'molecular matchmakers', which would use ATP for transient conformational changes promoting protein-DNA interactions [109].…”

Section: Domains Of Orf1 and Orf2 Proteins In The Is21 Familymentioning

confidence: 99%

Transposase and cointegrase: specialized transposition proteins of the bacterial insertion sequence IS21 and related elements

Berger

Haas

2001

CMLS, Cell. Mol. Life Sci.

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The bacterial insertion sequence IS21 shares with many insertion sequences a two-step, reactive junction transposition pathway, for which a model is presented in this review: a reactive junction with abutted inverted repeats is first formed and subsequently integrated into the target DNA. The reactive junction occurs in IS21-IS21 tandems and IS21 minicircles. In addition, IS21 shows a unique specialization of transposition functions. By alternative translation initiation, the transposase gene codes for two products: the transposase, capable of promoting both steps of the reactive junction pathway, and the cointegrase, which only promotes the integration of reactive junctions but with higher efficiency. This review also includes a survey of the IS21 family and speculates on the possibility that other members present a similar transpositional specialization.

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Molecular Characterization of an Aberrant Mercury Resistance Transposable Element from an Environmental Acinetobacter Strain

Cited by 33 publications

References 0 publications

Intercontinental spread of promiscuous mercury‐resistance transposons in environmental bacteria

Intercontinental spread of promiscuous mercury‐resistance transposons in environmental bacteria

Transposons Tn 1696 and Tn 21 and Their Integrons In4 and In2 Have Independent Origins

Transposase and cointegrase: specialized transposition proteins of the bacterial insertion sequence IS21 and related elements

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