Bacteriophage defence systems in lactic acid bacteria

Forde, Amanda; Fitzgerald, Gerald F.

doi:10.1007/978-94-017-2027-4_4

Cited by 106 publications

(142 citation statements)

References 111 publications

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“…These measures can be divided into four groups: (i) inhibition of phage adsorption, (ii) blockage of phage DNA injection, (iii) abortive infection mechanisms, and (iv) restriction of phage DNA (Forde & Fitzgerald, 1999;Coffey & Ross, 2002). These defence mechanisms are often located on plasmids.…”

Section: Introductionmentioning

confidence: 99%

“…Their enemies are not people who hate buttermilk, but virulent phages whose existence relies on propagation within bacterial cells. To combat phages, LAB have developed multiple molecular strategies.These measures can be divided into four groups: (i) inhibition of phage adsorption, (ii) blockage of phage DNA injection, (iii) abortive infection mechanisms, and (iv) restriction of phage DNA (Forde & Fitzgerald, 1999;Coffey & Ross, 2002). These defence mechanisms are often located on plasmids.…”

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confidence: 99%

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Characterization of the LlaCI methyltransferase from Lactococcus lactis subsp. cremoris W15 provides new insights into the biology of type II restriction–modification systems

2003

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The gene encoding the LlaCI methyltransferase (M.LlaCI) from Lactococcus lactis subsp. cremoris W15 was overexpressed in Escherichia coli. The enzyme was purified to apparent homogeneity using three consecutive steps of chromatography on phosphocellulose, blue-agarose and Superose 12HR, yielding a protein of M r 31 300±1000 under denaturing conditions. The exact position of the start codon AUG was determined by protein microsequencing. This enzyme recognizes the specific palindromic sequence 59-AAGCTT-39. Purified M.LlaCI was characterized. Unlike many other methyltransferases, M.LlaCI exists in solution predominantly as a dimer. It modifies the first adenine residue at the 59 end of the specific sequence to N 6 -methyladenine and thus is functionally identical to the corresponding methyltransferases of the HindIII (Haemophilus influenzae Rd) and EcoVIII (Escherichia coli E1585-68) restriction-modification systems. This is reflected in the identity of M.LlaCI with M.HindIII and M.EcoVIII noted at the amino acid sequence level (50 % and 62 %, respectively) and in the presence of nine sequence motifs conserved among N 6 -adenine b-class methyltransferases. However, polyclonal antibodies raised against M.EcoVIII cross-reacted with M.LlaCI but not with M.HindIII. Restriction endonucleases require Mg 2+ for phosphodiester bond cleavage. Mg 2+ was shown to be a strong inhibitor of the M.LlaCI enzyme and its isospecific homologues. This observation suggests that sensitivity of the M.LlaCI to Mg 2+ may strengthen the restriction activity of the cognate endonuclease in the bacterial cell. Other biological implications of this finding are also discussed. INTRODUCTIONLactic acid bacteria (LAB) are probiotic micro-organisms that have been used for millennia in the processing of dairy products. It was shown recently that dairy establishments in Britain can be dated back to 5000 years BC (Copley et al., 2003). Manufacturing of food such as cheese and yogurt, but also sauerkraut and dill pickles, as well as the existence of some regional cuisine, is heavily dependent on lactic fermentation. LAB and food processed by them therefore have armies of admirers, but on the other side, these bacteria have also powerful enemies. Their enemies are not people who hate buttermilk, but virulent phages whose existence relies on propagation within bacterial cells. To combat phages, LAB have developed multiple molecular strategies.These measures can be divided into four groups: (i) inhibition of phage adsorption, (ii) blockage of phage DNA injection, (iii) abortive infection mechanisms, and (iv) restriction of phage DNA (Forde & Fitzgerald, 1999;Coffey & Ross, 2002). These defence mechanisms are often located on plasmids. That feature can facilitate their horizontal spread among LAB and when acquired affords them protection against phage invasion (Allison & Klaenhammer, 1998). Among the defence mechanisms listed above, restriction-modification (R-M) systems form the most diverse group. Based on their molecular structure and cofactor requireme...

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Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Characterization of the LlaCI methyltransferase from Lactococcus lactis subsp. cremoris W15 provides new insights into the biology of type II restriction–modification systems

2003

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“…These include surface alterations to avoid phage adsorption, prevention of phage DNA injection, restriction of incoming DNA, acquiring phage-specific immunity through clustered regularly interspaced short palindromic repeats (7) and abortive infection (Abi). Abi systems provide population protection by promoting ''altruistic suicide'' of an infected bacterium (8). The majority of Abis have been found on plasmids of Gram-positive lactococcal strains (9), but some have been found in Gram-negative species, including Escherichia coli, Vibrio cholerae, and Shigella dysenteriae (10)(11)(12).…”

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confidence: 99%

The phage abortive infection system, ToxIN, functions as a protein–RNA toxin–antitoxin pair

Fineran

Blower

Foulds

et al. 2009

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

481

545

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Various mechanisms exist that enable bacteria to resist bacteriophage infection. Resistance strategies include the abortive infection (Abi) systems, which promote cell death and limit phage replication within a bacterial population. A highly effective 2-gene Abi system from the phytopathogen Erwinia carotovora subspecies atroseptica, designated ToxIN, is described. The ToxIN Abi system also functions as a toxin-antitoxin (TA) pair, with ToxN inhibiting bacterial growth and the tandemly repeated ToxI RNA antitoxin counteracting the toxicity. TA modules are currently divided into 2 classes, protein and RNA antisense. We provide evidence that ToxIN defines an entirely new TA class that functions via a novel protein-RNA mechanism, with analogous systems present in diverse bacteria. Despite the debated role of TA systems, we demonstrate that ToxIN provides viral resistance in a range of bacterial genera against multiple phages. This is the first demonstration of a novel mechanistic class of TA systems and of an Abi system functioning in different bacterial genera, both with implications for the dynamics of phage-bacterial interactions.Bacteriophage ͉ Bacteriostasis ͉ Erwinia ͉ plasmid ͉ resistance

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“…Triplicate results indicated that > 99% of /c2 adsorbed to the transconjugant DPC5101 thus eliminating the possibility of an adsorption inhibition (Ads) system for this phage being present on the plasmid. Given the observed reduction in plaque size for phage c2 and the total resistance against phage 712, the pCBG104 resistance system has similarities to many lactococcal abortive infection mechanisms previously reported (for review see Forde and Fitzgerald 1999). Analysis of intracellular phage c2 and phage 712 DNA replication revealed that the increase in phage DNA content of cells following infection was delayed in the presence of pCBG104.…”

Section: Identification Of Bacteriocin-linked Bacteriophage Resistancmentioning

confidence: 66%

“…Nevertheless, bacteriophage sensitivity can be remedied by targeted strain improvement, which focuses on the introduction of plasmids harbouring specific phage resistance genes (Klaenhammer and Fitzgerald 1994;Forde and Fitzgerald 1999). Such approaches to strain improvement require that the plasmid contains a suitable marker for selection of transconjugants.…”

Section: Introductionmentioning

confidence: 99%

Use of lacticin 481 to facilitate delivery of the bacteriophage resistance plasmid, pCBG104 to cheese starters

et al. 2002

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Bacteriophage defence systems in lactic acid bacteria

Cited by 106 publications

References 111 publications

Characterization of the LlaCI methyltransferase from Lactococcus lactis subsp. cremoris W15 provides new insights into the biology of type II restriction–modification systems

Characterization of the LlaCI methyltransferase from Lactococcus lactis subsp. cremoris W15 provides new insights into the biology of type II restriction–modification systems

The phage abortive infection system, ToxIN, functions as a protein–RNA toxin–antitoxin pair

Use of lacticin 481 to facilitate delivery of the bacteriophage resistance plasmid, pCBG104 to cheese starters

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