These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Molecular characterization of plasmids pS7a and pS7b from Lactococcus lactis subsp. lactis bv. diacetylactis S50 as a base for the construction of mobilizable cloning vectors.
    Author: Strahinic I, Kojic M, Tolinacki M, Fira D, Topisirovic L.
    Journal: J Appl Microbiol; 2009 Jan; 106(1):78-88. PubMed ID: 19040703.
    Abstract:
    AIMS: Strain Lactococcus lactis subsp. lactis bv. diacetylactis S50 harbours five theta-replicating plasmids (pS6, pS7a, pS7b, pS80 and pS140). The aim of this study was to characterize domains involved in the replication and conjugative mobilization of the small plasmids pS7a and pS7b, which are structurally very similar. METHODS AND RESULTS: Complete nucleotide sequences of pS7a and pS7b were determined by cloning DNA fragments of different sizes into Escherichia coli vectors. Linearized plasmids and four EcoRI fragments of the pS7a and pS7b were cloned into an origin probe vector. Constructed plasmids (pSEV10, pSK10, pISE1a and pISE1b) were able to replicate in the strain L. lactis subsp. cremoris MG1363. In addition, experiments showed that plasmids pS7a and pS7b contained oriT sequences and their conjugative transfer directly depended on the presence of pS80 in donor cells. CONCLUSIONS: Plasmids pS7a and pS7b contained typical lactococcal theta replication origin and repB gene that enable them to replicate in the strain L. lactis subsp. cremoris MG1363. Plasmid pS80 plays a key role in the conjugative transfer of small plasmids. SIGNIFICANCE AND IMPACT OF THE STUDY: Plasmids pS7a and pS7b-based derivatives could be valuable tools for genetic manipulation, studying processes of plasmid maintenance and horizontal gene transfer in lactococci.
    [Abstract] [Full Text] [Related] [New Search]