| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Biochemistry and Microbiology, Faculté des Sciences et de Génie, Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Québec, Canada, G1K 7P4
2 Department of Food Science and Nutrition, Centre de Recherche en Science et Technologie du Lait (STELA), Faculté des Sciences de l'Agriculture et de l'Alimentation, Université Laval, Québec, Canada, G1K 7P4
The three Lactococcus lactis plasmids pSRQ700, pSRQ800, and pSRQ900 encode the previously described anti-phage resistance mechanisms LlaDCHI, AbiK, and AbiQ, respectively. Since these plasmids are likely to be introduced into industrial Lactococcus lactis strains used to manufacture commercial fermented dairy products, their complete DNA sequences were determined and analyzed. The plasmids pSRQ700 (7784 bp), pSRQ800 (7858 bp), and pSRQ900 (10,836 bp) showed a similar genetic organization including a common lactococcal theta-type replicon. A second replication module showing features of the pMV158 family of rolling circle replicons was also found on pSRQ700. The theta replication regions of the three plasmids were associated with two additional coding regions, one of which encodes for HsdS, the specificity subunit of the type I restriction/modification system. When introduced into L. lactis IL1403, the HsdS of pSRQ800 and pSRQ900 conferred a weak resistance against phage P008 (936 species). These results indicated that both HsdS subunits can complement the chromosomally encoded type I restriction/modification system in IL1403. The genes involved in the phage resistance systems LlaDCHI, AbiK, and AbiQ were found in close proximity to and downstream of the replication modules. In pSRQ800 and pSRQ900, transfer origins and putative tyrosine recombinases were found upstream of the theta replicons. Genes encoding recombination proteins were also found on pSRQ700. Finally, open reading frames associated with bacteriocin production were found on pSRQ900, but no anti-lactococcal activity was detected. Based on our current knowledge, these three plasmids are safe and suitable for food-grade applications.
Submitted on August 25, 2000
This article has been cited by other articles:
|
|
 |
|
  Y. Li, C. Canchaya, F. Fang, E. Raftis, K. A. Ryan, J.-P. van Pijkeren, D. van Sinderen, and P. W. O'Toole Distribution of Megaplasmids in Lactobacillus salivarius and Other Lactobacilli J. Bacteriol., September 1, 2007; 189(17): 6128 - 6139. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Dziewit, M. Jazurek, L. Drewniak, J. Baj, and D. Bartosik The SXT Conjugative Element and Linear Prophage N15 Encode Toxin-Antitoxin-Stabilizing Systems Homologous to the tad-ata Module of the Paracoccus aminophilus Plasmid pAMI2 J. Bacteriol., March 1, 2007; 189(5): 1983 - 1997. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. J. Labrie and S. Moineau Abortive Infection Mechanisms and Prophage Sequences Significantly Influence the Genetic Makeup of Emerging Lytic Lactococcal Phages J. Bacteriol., February 15, 2007; 189(4): 1482 - 1487. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. O'Driscoll, F. Glynn, G. F. Fitzgerald, and D. v. Sinderen Sequence Analysis of the Lactococcal Plasmid pNP40: a Mobile Replicon for Coping with Environmental Hazards. J. Bacteriol., September 1, 2006; 188(18): 6629 - 6639. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. J. Siezen, B. Renckens, I. van Swam, S. Peters, R. van Kranenburg, M. Kleerebezem, and W. M. de Vos Complete Sequences of Four Plasmids of Lactococcus lactis subsp. cremoris SK11 Reveal Extensive Adaptation to the Dairy Environment Appl. Envir. Microbiol., December 1, 2005; 71(12): 8371 - 8382. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L.-C. Fortier, J. D. Bouchard, and S. Moineau Expression and Site-Directed Mutagenesis of the Lactococcal Abortive Phage Infection Protein AbiK J. Bacteriol., June 1, 2005; 187(11): 3721 - 3730. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C.-A. Alpert, A.-M. Crutz-Le Coq, C. Malleret, and M. Zagorec Characterization of a Theta-Type Plasmid from Lactobacillus sakei: a Potential Basis for Low-Copy-Number Vectors in Lactobacilli Appl. Envir. Microbiol., September 1, 2003; 69(9): 5574 - 5584. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Boucher, M. Parrot, H. Gaudreau, C. P. Champagne, C. Vadeboncoeur, and S. Moineau Novel Food-Grade Plasmid Vector Based on Melibiose Fermentation for the Genetic Engineering of Lactococcus lactis Appl. Envir. Microbiol., December 1, 2002; 68(12): 6152 - 6161. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
