Identification and Cloning of Plasmid Deoxyribonucleic Acid Coding for Abortive Phage Infection from Streptococcus lactis ssp. diacetylactis KR2

Laible, Nancy J.; Rule, Patricia; Harlander, Susan K.; McKay, Larry L.

doi:10.3168/jds.s0022-0302(87)80280-1

Cited by 35 publications

(30 citation statements)

References 22 publications

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“…We suggested that the finding of a phage-insensitive determinant located on a conjugative plasmid should prove useful in constructing phage-insensitive strains for dairy fermentation processes. Although we later found other plasmids coding for phage insensitivity (Laible et al 1987;Froseth et al 1988a;Murphy et al 1988;McKay et al 1989;McLandsborough et al 1995McLandsborough et al , 1998, this area, showing that plasmids in lactococci coded for a variety of phage-insensitive mechanisms and the construction of phage-insensitive strains based on acquisition of plasmids coding for phage insensitivity, was developed and pioneered by Todd Klaenhammer's group at North Carolina State University.…”

Section: Plasmids Coding For Bacteriophage Resistancementioning

confidence: 99%

An Amazing Journey

McKay

2015

Annu. Rev. Food Sci. Technol.

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This article describes my early life and the chance events leading to my becoming a microbiologist and then my embarking on a career developing the plasmid biology and genetics of lactococci used in milk fermentations. MY LIFE: THE FIRST 18 YEARSWhy and how did I become a scientist? I attempt to present my background and the series of events that led to a successful career in the area of dairy starter cultures. The latter seemed to be by chance and serendipity. I was born in Oregon in 1943. My Dad never completed the sixth grade, and both my parents had a strong work ethic. By the time I was 10, I could saw wood with a crosscut and handle an ax to split the wood. I also worked picking berries on a farm and could "out pick" everyone except for two adult workers, and I was the only one allowed to pick in special sections with them. In essence, at an early age I, too, acquired a strong work ethic and was motivated to do my best at whatever task I encountered. When I was 11, my parents lost everything. I had come home from school to find a trailer hitched to our car with our household belongings loaded onto it. We moved around and I attended school for a week in one place and a month in another until we moved to Montana. There, my parents purchased a one-room cabin without running water, which was located on a lakefront property approximately 12 miles east of Kalispell. Our family of five lived in that one room for a year before my parents bought a home on an adjacent lot. Because of the move to Montana, I never completed the sixth grade but was allowed to start the seventh grade. The two-room school had four grades in each room and one teacher for each room. I had a stuttering problem and did not want the other kids in the school to know. So, for the first six weeks I would not respond when called on in class. When asked about this at the first parent/teacher conference, my mom answered that I was probably afraid of stuttering. The teacher never pushed the issue, and eventually I was comfortable responding in class. Even then I must have been a determined individual! Although I never stuttered again, this early issue is likely related to my feeling comfortable advising students (see Table 1) one-on-one but not always feeling comfortable speaking to groups of people, unless I am well prepared.For the next six years, living by the lake and mountains was paradise, a dream (swimming, ice skating, fishing, water and snow skiing, hiking in the mountains, and seeing the local wildlife). The home my parents had purchased was a small two-bedroom dwelling, so my brother and I slept in the attic above the garage. We slept there year-round, even though the space was unheated. The Montana winters do indeed get cold, and the coldest night in the five years we slept there was minus 39• C. It must have been good for my health because from the eighth grade to the end of high school I never missed a day of school. After I was in my profession, my mom told me that upon graduating from the eighth grade, the high school counse...

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Section: Plasmids Coding For Bacteriophage Resistancementioning

confidence: 99%

An Amazing Journey

McKay

2015

Annu. Rev. Food Sci. Technol.

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“…lactis biovar diacetylactis KR2 and was shown to encode two distinct bacteriophage resistance mechanisms, an R/M system and an Abi system (22,25). The nucleotide sequence of a 16,174-bp HpaII segment of pKR223 encompassing both the R/M and Abi systems was obtained, allowing the characterization of the R/M system, designated LlaKR2I (37), and partial characterization of the multigene Abi system, designated AbiR (38).…”

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confidence: 99%

Involvement of the LlaKR2I Methylase in Expression of the AbiR Bacteriophage Defense System in Lactococcus lactis subsp. lactis biovar diacetylactis KR2

Yang

DeUrraza²,

Matvienko³

et al. 2006

J Bacteriol

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The native lactococcal plasmid, pKR223, from Lactococcus lactis subsp. lactis biovar diacetylactis KR2 encodes two distinct bacteriophage-resistant mechanisms, the LlaKR2I restriction and modification (R/M) system and the abortive infection (Abi) mechanism, AbiR, that impedes bacteriophage DNA replication. This study completed the characterization of AbiR, revealing that it is the first Abi system to be encoded by three genes, abiRa, abiRb, and abiRc, arranged in an operon and that it requires the methylase gene from the LlaKR2I R/M system. An analysis of deletion and insertion clones demonstrated that the AbiR operon was toxic in L. lactis without the presence of the LlaKR2I methylase, which is required to protect L. lactis from AbiR toxicity. The novelty of the AbiR system resides in its original gene organization and the unusual protective role of the LlaKR2I methylase. Interestingly, the AbiR genetic determinants are flanked by two IS982 elements generating a likely transposable AbiR composite. This observation not only substantiated the novel function of the LlaKR2I methylase in the AbiR system but also illustrated the evolution of the LlaKR2I methylase toward a new and separate cellular function. This unique structure of both the LlaKR2I R/M system and the AbiR system may have contributed to the evolution of the LlaKR2I methylase toward a novel role comparable to that of the cell cycle-regulated methylases that include Dam and CcrM methylases. This new role for the LlaKR2I methylase offers a unique snapshot into the evolution of the cell cycle-regulated methylases from an existing R/M system.

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“…lactis bv. diacetylactis KR2 and was shown to mediate two distinct mechanisms of resistance to bacteriophage infection, an R/M system and an Abi system (20,23). The sequence and genetic characterization of the R/M system (designated LlaKR2I) have been reported previously (31).…”

mentioning

confidence: 99%

Characterization of AbiR, a Novel Multicomponent Abortive Infection Mechanism Encoded by Plasmid pKR223 of Lactococcus lactis subsp. lactis KR2

Twomey

Urraza

McKay

et al. 2000

Appl Environ Microbiol

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The native lactococcal plasmid pKR223 encodes two distinct phage resistance mechanisms, a restriction and modification (R/M) system designated LlaKR2I and an abortive infection mechanism (Abi) which affects prolate-headed-phage proliferation. The nucleotide sequence of a 16,174-bp segment of pKR223 encompassing both the R/M and Abi determinants has been determined, and sequence analysis has validated the novelty of the Abi system, which has now been designated AbiR. Analysis of deletion and insertion clones demonstrated that AbiR was encoded by two genetic loci, separated by the LlaKR2I R/M genes. Mechanistic studies on the AbiR phenotype indicated that it was heat sensitive and that it impeded phage DNA replication. These data indicated that AbiR is a novel multicomponent, heat-sensitive, "early"-functioning Abi system and is the first lactococcal Abi system described which is encoded by two separated genetic loci.

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Identification and Cloning of Plasmid Deoxyribonucleic Acid Coding for Abortive Phage Infection from Streptococcus lactis ssp. diacetylactis KR2

Cited by 35 publications

References 22 publications

An Amazing Journey

An Amazing Journey

Involvement of the LlaKR2I Methylase in Expression of the AbiR Bacteriophage Defense System in Lactococcus lactis subsp. lactis biovar diacetylactis KR2

Characterization of AbiR, a Novel Multicomponent Abortive Infection Mechanism Encoded by Plasmid pKR223 of Lactococcus lactis subsp. lactis KR2

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