Localization, cloning, and expression of genetic determinants for bacteriophage resistance (Hsp) from the conjugative plasmid pTR2030

Hill, Colin; Romero, Dennis; McKenney, David; Finer, Kim R.; Klaenhammer, Todd R.

doi:10.1128/aem.55.7.1684-1689.1989

Cited by 43 publications

(21 citation statements)

References 29 publications

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“…To determine whether the region of phage-plasmid homology could be further localized, hybridization experiments were conducted with pTK6 (Hsp+ R+/M+) and pTRK18 (Hsp+ R-/M-). pTK6 is a recombinant plasmid carrying the 11.5-kb phage resistance region of pTR2030, and pTRK18 is a deletion derivative of pTK6 that is deficient in R/M activities (12,13). Phage 450 hybridized to pTK6 but not to pTRK18 (data not shown).…”

Section: Resultsmentioning

confidence: 97%

“…Further hybridization experiments revealed that phage 4)50 did not hybridize with pTR2023, a derivative of pTR2030 with an 11.5-kb deletion. Contained within this 11.5-kb region on pTR2030 are the genetic determinants for Hsp+ and R+/M+ (10,12,13). To determine whether the region of phage-plasmid homology could be further localized, hybridization experiments were conducted with pTK6 (Hsp+ R+/M+) and pTRK18 (Hsp+ R-/M-).…”

Section: Resultsmentioning

confidence: 99%

“…One of the most thoroughly characterized lactococcal phage resistance plasmids is pTR2030 (10,12,13,23,31). This self-transmissible plasmid encodes both R/M and Hsp functions; the latter is an Abi mechanism originally designated as Hsp to describe the heat-sensitive reduction in burst size and efficiency of plaquing of phage c2 during abortive infection on pTR2030 transconjugants (13,23). Different phage species appear to vary in their general susceptibility to pTR2030.…”

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confidence: 99%

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Molecular Characterization of Three Small Isometric-Headed Bacteriophages Which Vary in Their Sensitivity to the Lactococcal Phage Resistance Plasmid pTR2030

Alatossava

Klaenhammer

1991

Appl Environ Microbiol

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Lactococcus lactis LMA12-4 is a pTR2030 transconjugant that has been used as an industrial starter culture because of its resistance to phages predominant in cheese plants. Plasmid pTR2030 interferes with susceptible phages in this host strain via two mechanisms, restriction and modification (R/M) and abortive infection (Hsp). After prolonged use of LMA12-4 transconjugants in the industry, two different bacteriophages, designated nck202.+48 (4)48) and nck202.+50 (+50), were isolated which could produce plaques on LMA12-4 containing pTR2030. In this study, these two phages were characterized and compared with a third phage, nck2O2.+31 (+31), which is susceptible to both the R/M and Hsp activities encoded by pTR2030. Phage +48 was not susceptible to inhibition by Hsp, whereas +50 was unaffected by either the R/M or Hsp mechanisms. All three were small isometric-headed phages, but small differences were noted between the phages in the structural details of the tail base plate, susceptibility to chloroform treatment, and requirements for calcium infectivity. The phage genomes were all between 29.9 and 31.9 kb in length. Phages +31 and +48 harbored cohesive ends, whereas the phage +50 genome was circularly permuted, terminally redundant, and carried a putative packaging initiation site. DNA-DNA hybridization experiments conducted between the phages revealed a common region in +48 and +50 that may correlate with the resistance of the two phages to the Hsp-abortive infection induced by pTR2030. Phage +50 also harbored DNA sequences that shared homology to pTR2030 in the region where R/M activities have been localized on the plasmid. Molecular characterization of the three phages localized regions within the genomes of the pTR2030-resistant phages that may be responsible for circumventing plasmid-encoded Hsp and R/M defense mechanisms in lactococci.

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Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

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confidence: 99%

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Molecular Characterization of Three Small Isometric-Headed Bacteriophages Which Vary in Their Sensitivity to the Lactococcal Phage Resistance Plasmid pTR2030

Alatossava

Klaenhammer

1991

Appl Environ Microbiol

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“…A second plasmid pCI829, which is indistinguishable from pTR2030, has been identified in the strain L. lactis subsp, cremoris UC811 [64,65]. pTR2030 is a conjugative plasmid which encodes at least two resistance determinants, Hsp and Llal [90,95]. The Llal R/M system has already been described above.…”

Section: Hspmentioning

confidence: 99%

Bacteriophage and bacteriophage resistance in lactic acid bacteria

Hill¹

1993

FEMS Microbiology Reviews

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The study of bacteriophage-host interactions has been instrumental in the development of genetic systems in many genera, and laid many of the foundations of modern molecular genetics. Research into bacteriophage and bacteriophage resistance in the lactic acid bacteria has moved into a new and exciting dimension in recent years. Mechanisms such as adsorption inhibition, restriction and modification, and abortive infection which have been detected and described phenotypically over the past decade are now being subjected to molecular analysis, and this has led to a better understanding of the nature and variety of resistance systems employed by lactic acid bacteria to combat phage attack. In addition, analysis of different bacteriophage has increased our knowledge of these ubiquitous particles to the point where it is possible to construct novel phage resistances based on the phage genome itself. This review outlines the recent progress in the molecular analysis of bacteriophage, bacteriophage resistance and counter resistance, and the construction of novel resistance mechanisms.

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“…A number of plasmids which encode resistance to bacteriophage in lactococci have been identified (4,13,17). The resistance mechanisms encoded by these plasmids include interference with phage adsorption (6,19), restriction modification (R/M) (3, 7-9, 18, 24), and abortive infection (7,8,10,11,(14)(15)(16). In general, these systems have been studied independently, and little is known regarding the cooperative or counteractive effects of combining defense mechanisms.…”

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confidence: 99%

The conjugative plasmid pTR2030 encodes two bacteriophage defense mechanisms in lactococci, restriction modification (R+/M+) and abortive infection (Hsp+)

Hill

Pierce

Klaenhammer

1989

Appl Environ Microbiol

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pTR2030 is a conjugative plasmid which encodes resistance to bacteriophage in lactococci by a mechanism that aborts the phage infection (Hsp+). Subcloning and in vivo deletion events showed that two independent mechanisms of resistance are located on a 13.6-kilobase BglII fragment cloned in pSA3; one mechanism is responsible for the abortive infection, and the other encodes a restriction modification system. The introduction of pTR2030 or the recombinant plasmid pTK6 resulted in the loss of a resident restriction modification plasmid in Lactococcus lactis NCK202 which was not previously identified.

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Localization, cloning, and expression of genetic determinants for bacteriophage resistance (Hsp) from the conjugative plasmid pTR2030

Abstract: Genetic determinants for a bacteriophage resistance mechanism (Hsp+) encoded by plasmid pTR2030 (46.2 kilobases [kb]) were localized by mapping an 11.5-kb deletion that accompanied the transition of Lactococcus lactis LMA12-4 transconjugants (M. E.

Cited by 43 publications

References 29 publications

Molecular Characterization of Three Small Isometric-Headed Bacteriophages Which Vary in Their Sensitivity to the Lactococcal Phage Resistance Plasmid pTR2030

Molecular Characterization of Three Small Isometric-Headed Bacteriophages Which Vary in Their Sensitivity to the Lactococcal Phage Resistance Plasmid pTR2030

Bacteriophage and bacteriophage resistance in lactic acid bacteria

The conjugative plasmid pTR2030 encodes two bacteriophage defense mechanisms in lactococci, restriction modification (R+/M+) and abortive infection (Hsp+)

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